title: Versatile Conjugated Polymer Nanoparticles for High-Resolution O2 Imaging in Cells and 3D Tissue Models.
abstract: High brightness, chemical and photostability, tunable characteristics, and spectral and surface properties are important attributes for nanoparticle probes designed for live cell imaging. We describe a class of nanoparticles for high-resolution imaging of O2 that consists of a substituted conjugated polymer (polyfluorene or poly(fluorene-alt-benzothiadiazole)) acting as a FRET antenna and a fluorescent reference with covalently bound phosphorescent metalloporphyrin (PtTFPP, PtTPTBPF). The nanoparticles prepared from such copolymers by precipitation method display stability, enhanced (>5-10 times) brightness under one- and two-photon excitation, compatibility with ratiometric and lifetime-based imaging modes, and low toxicity for cells. Their cell-staining properties can be modulated with positively and negatively charged groups grafted to the backbone. The "zwitter-ionic" nanoparticles show high cell-staining efficiency, while their cell entry mechanisms differ for the different 3D models. When injected in the bloodstream, the cationic and anionic nanoparticles show similar distribution in vivo. These features and tunable properties make the conjugated polymer based phosphorescent nanoparticles a versatile tool for quantitative O2 imaging with a broad range of cell and 3D tissue models.
authors: †School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland.
authors: Ruslan I
authors: RI
authors: Dmitriev
authors: ‡Institute of Analytical Chemistry and Food Chemistry, Graz University of Technology, Graz 8010, Austria.
authors: Sergey M
authors: SM
authors: Borisov
authors: §Department of Physiology and Medical Physics, Centre for the Study of Neurological Disorders, Royal College of Surgeons in Ireland, Dublin 2, Ireland.
authors: Heiko
authors: H
authors: Düssmann
authors: ‡Institute of Analytical Chemistry and Food Chemistry, Graz University of Technology, Graz 8010, Austria.
authors: Shiwen
authors: S
authors: Sun
authors: ‡Institute of Analytical Chemistry and Food Chemistry, Graz University of Technology, Graz 8010, Austria.
authors: Bernhard J
authors: BJ
authors: Müller
authors: §Department of Physiology and Medical Physics, Centre for the Study of Neurological Disorders, Royal College of Surgeons in Ireland, Dublin 2, Ireland.
authors: Jochen
authors: J
authors: Prehn
authors: ∥Department of Medicinal Nanobiotechnology, Pirogov Russian State Medical University, Moscow 115682, Russia.|⊥Federal Research Clinical Centre of Federal Medical and Biological Agency of Russia, Moscow, Russia.
authors: Vladimir P
authors: VP
authors: Baklaushev
authors: ‡Institute of Analytical Chemistry and Food Chemistry, Graz University of Technology, Graz 8010, Austria.
authors: Ingo
authors: I
authors: Klimant
authors: †School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland.
authors: Dmitri B
authors: DB
authors: Papkovsky
mesh_terms: D000818:Animals; D001692:Biological Transport; D002460:Cell Line; D002470:Cell Survival; D005260:Female; D042541:Intracellular Space / Q000378:metabolism; D007700:Kinetics; D051379:Mice; D008958:Models, Molecular; D057054:Molecular Imaging / Q000379:methods*; D053758:Nanoparticles / Q000737:chemistry*; D010100:Oxygen / Q000378:metabolism*; D011108:Polymers / Q000737:chemistry* / Q000378:metabolism / Q000493:pharmacokinetics; D014018:Tissue Distribution
chemical_list: D011108:Polymers; D010100:Oxygen
keywords: 3D tissue model; cell and tissue oxygenation; cell-penetrating nanoparticle probe; conjugated polymer; imaging; molecular oxygen; phosphorescence quenching