title: Nanoparticles as drug delivery system against tuberculosis in zebrafish embryos: direct visualization and treatment.
abstract: Nanoparticles (NPs) enclosing antibiotics have provided promising therapy against Mycobacterium tuberculosis (Mtb) in different mammalian models. However, the NPs were not visualized in any of these animal studies. Here, we introduce the transparent zebrafish embryo as a system for noninvasive, simultaneous imaging of fluorescent NPs and the fish tuberculosis (TB) agent Mycobacterium marinum (Mm). The study was facilitated by the use of transgenic lines of macrophages, neutrophils, and endothelial cells expressing fluorescent markers readily visible in the live vertebrate. Intravenous injection of Mm led to phagocytosis by blood macrophages. These remained within the vasculature until 3 days postinfection where they started to extravasate and form aggregates of infected cells. Correlative light/electron microscopy revealed that these granuloma-like structures had significant access to the vasculature. Injection of NPs induced rapid uptake by both infected and uninfected macrophages, the latter being actively recruited to the site of infection, thereby providing an efficient targeting into granulomas. Rifampicin-loaded NPs significantly improved embryo survival and lowered bacterial load, as shown by quantitative fluorescence analysis. Our results argue that zebrafish embryos offer a powerful system for monitoring NPs in vivo and rationalize why NP therapy was so effective against Mtb in earlier studies; bacteria and NPs share the same cellular niche.
authors.affiliation: Department of Biosciences, University of Oslo , Blindernveien 31, 0371 Oslo, Norway.
authors.forename: Federico
authors.initials: F
authors.lastname: Fenaroli
authors.forename: David
authors.initials: D
authors.lastname: Westmoreland
authors.forename: Jørgen
authors.initials: J
authors.lastname: Benjaminsen
authors.forename: Terje
authors.initials: T
authors.lastname: Kolstad
authors.forename: Frode Miltzow
authors.initials: FM
authors.lastname: Skjeldal
authors.forename: Annemarie H
authors.initials: AH
authors.lastname: Meijer
authors.forename: Michiel
authors.initials: M
authors.lastname: van der Vaart
authors.forename: Lilia
authors.initials: L
authors.lastname: Ulanova
authors.forename: Norbert
authors.initials: N
authors.lastname: Roos
authors.forename: Bo
authors.initials: B
authors.lastname: Nyström
authors.forename: Jon
authors.initials: J
authors.lastname: Hildahl
authors.forename: Gareth
authors.initials: G
authors.lastname: Griffiths
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology; D001692:Biological Transport; D003374:Coumarins / Q000737:chemistry; D004337:Drug Carriers / Q000737:chemistry* / Q000378:metabolism; D004625:Embryo, Nonmammalian / Q000382:microbiology*; D006099:Granuloma / Q000382:microbiology; D019344:Lactic Acid / Q000737:chemistry; D008264:Macrophages / Q000382:microbiology; D009165:Mycobacterium Infections, Nontuberculous / Q000188:drug therapy / Q000382:microbiology; D019910:Mycobacterium marinum / Q000187:drug effects* / Q000502:physiology; D053758:Nanoparticles / Q000737:chemistry*; D061848:Optical Imaging; D011100:Polyglycolic Acid / Q000737:chemistry; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D012235:Rhodamines / Q000737:chemistry; D012293:Rifampin / Q000737:chemistry / Q000494:pharmacology; D013844:Thiazoles / Q000737:chemistry; D014376:Tuberculosis / Q000382:microbiology / Q000662:veterinary; D015027:Zebrafish / Q000196:embryology* / Q000382:microbiology*
chemical_list: D000900:Anti-Bacterial Agents; D003374:Coumarins; D004337:Drug Carriers; D012235:Rhodamines; D013844:Thiazoles; C517282:coumarin 6; C105720:rhodamine 800; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D012293:Rifampin