title: Polymeric nanosensors for measuring the full dynamic pH range of endosomes and lysosomes in mammalian cells.
abstract: Polymer nanoparticle sensors have been constructed for studying pH in the endocytic pathway in mammalian cells. The pH sensors for fluorescence ratiometric measurements were prepared using inverse microemulsion polymerization with rhodamine as reference fluorophor and fluorescein and oregon green as pH sensitive dyes, which gave a dynamic pH measurement range from 4.1-7.5. Thus, the sensors cover the pH range of almost all intracellular compartments in mammalian cells. Both neutral and cationic polyacrylamide particles were synthesized where (3-acrylamidopropyl) trimethylammonium chloride was used to introduce a net positive charge in the cationic particles. It was found that the positively charged particle sensors were internalized spontaneously by HepG2 cancer cells. These new pH nanosensors are potential tools in time resolved quantification of pH in the endocytic pathway of living cells.
authors.affiliation: Technical University of Denmark, Department of Micro- and Nanotechnology, Frederiksborgvej 399, 4000 Roskilde, Denmark.
authors.forename: Honghao
authors.initials: H
authors.lastname: Sun
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Andresen
authors.forename: Rikke V
authors.initials: RV
authors.lastname: Benjaminsen
authors.forename: Kristoffer
authors.initials: K
authors.lastname: Almdal
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation*; D011992:Endosomes / Q000737:chemistry*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D056945:Hep G2 Cells; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008247:Lysosomes / Q000737:chemistry*; D015336:Molecular Probe Techniques / Q000295:instrumentation*; D036103:Nanotechnology / Q000295:instrumentation*; D013050:Spectrometry, Fluorescence / Q000295:instrumentation*; D000099166:Polyacrylamides
chemical_list: D000180:Acrylic Resins; D000099166:Polyacrylamides