title: Fabrication of triple-labeled polyelectrolyte microcapsules for localized ratiometric pH sensing.
abstract: Encapsulation of pH sensitive fluorophores as reporting molecules provides a powerful approach to visualize the transportation of multilayer capsules. In this study, two pH sensitive dyes (fluorescein and oregon green) and one pH insensitive dye (rhodamine B) were simultaneously labeled on the microcapsules to fabricate ratiometric pH sensors. The fluorescence of the triple-labeled microcapsule sensors was robust and nearly independent of other intracellular species. With a dynamic pH measurement range of 3.3-6.5, the microcapsules can report their localized pH at a real time. Cell culture experiments showed that the microcapsules could be internalized by RAW 246.7 cells naturally and finally accumulated in acidic organelles with a pH value of 5.08 ± 0.59 (mean ± s.d.; n=162).
authors.affiliation: MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University in Hangzhou, 310027 Hangzhou, China.
authors.forename: Xiaoxue
authors.initials: X
authors.lastname: Song
authors.affiliation: MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University in Hangzhou, 310027 Hangzhou, China.
authors.forename: Huanbin
authors.initials: H
authors.lastname: Li
authors.affiliation: MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University in Hangzhou, 310027 Hangzhou, China. Electronic address: tongwj@zju.edu.cn.
authors.forename: Weijun
authors.initials: W
authors.lastname: Tong
authors.affiliation: MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University in Hangzhou, 310027 Hangzhou, China.
authors.forename: Changyou
authors.initials: C
authors.lastname: Gao
mesh_terms: D000818:Animals; D002214:Capsules / Q000378:metabolism* / Q000494:pharmacology; D002264:Carboxylic Acids / Q000737:chemistry; D002460:Cell Line; D048271:Chitosan / Q000737:chemistry; D016264:Dextran Sulfate / Q000737:chemistry; D004337:Drug Carriers / Q000737:chemistry / Q000378:metabolism*; D004339:Drug Compounding; D004705:Endocytosis; D019793:Fluorescein / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D008264:Macrophages / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D051379:Mice; D057054:Molecular Imaging / Q000379:methods*; D011073:Polyamines / Q000737:chemistry; D012235:Rhodamines / Q000737:chemistry; D013050:Spectrometry, Fluorescence / Q000379:methods*
chemical_list: D002214:Capsules; D002264:Carboxylic Acids; D004337:Drug Carriers; C436864:Oregon Green 488 carboxylic acid; D011073:Polyamines; D012235:Rhodamines; C063994:polyallylamine; D048271:Chitosan; D016264:Dextran Sulfate; C029773:rhodamine B; D019793:Fluorescein
keywords: Cell uptake; Layer-by-layer; Polyelectrolyte microcapsule; Ratiometric measurement; pH sensing