title: Mesoporous silica nanoparticles as a compound delivery system in zebrafish embryos.
abstract: Silica nanoparticles can be efficiently employed as carriers for therapeutic drugs in vitro. Here, we use zebrafish embryos as a model organism to see whether mesoporous silica nanoparticles (MSNPs) can be incorporated to deliver compounds in vivo. We injected 35-40 nL (10 mg/mL) of custom-synthesized, fluorescently-tagged 200 nm MSNPs into the left flank, behind the yolk sac extension, of 2-day-old zebrafish embryos. We tracked the distribution and translocation of the MSNPs using confocal laser scanning microscopy. Some of the particles remained localized at the injection site, whereas others entered the bloodstream and were carried around the body. Embryo development and survival were not significantly affected by MSNP injection. Acridine orange staining revealed that MSNP injections did not induce significant cell death. We also studied cellular immune responses by means of lysC::DsRED2 transgenic embryos. MSNP-injected embryos showed infiltration of the injection site with neutrophils, similar to controls injected with buffer only. In the same embryos, counterstaining with L-plastin antibody for leukocytes revealed the same amount of cellular infiltration of the injection site in embryos injected with MSNPs or with buffer only. Next, we used MSNPs to deliver two recombinant cytokines (macrophage colony-stimulating factor and receptor for necrosis factor ligand) to zebrafish embryos. These proteins are known to activate cells involved in bone remodeling, and this can be detected with the marker tartrate-resistant acid phosphatase. Coinjection of these proteins loaded onto MSNPs produced a significant increase in the number of tartrate-resistant acid phosphatase-positive cells after 2-3 days of injection. Our results show that MSNPs can be used to deliver bioactive compounds into zebrafish larvae without producing higher mortality or gross evidence of teratogenicity.
authors.affiliation: Department of Integrative Zoology, Institute of Biology, Gorlaeus Laboratories, Leiden University, Leiden, The Netherlands.
authors.forename: Faiza
authors.initials: F
authors.lastname: Sharif
authors.forename: Fabiola
authors.initials: F
authors.lastname: Porta
authors.forename: Annemarie H
authors.initials: AH
authors.lastname: Meijer
authors.forename: Alexander
authors.initials: A
authors.lastname: Kros
authors.forename: Michael K
authors.initials: MK
authors.lastname: Richardson
mesh_terms: D000135:Acid Phosphatase / Q000378:metabolism; D000818:Animals; D030801:Animals, Genetically Modified; D017209:Apoptosis / Q000187:drug effects; D004337:Drug Carriers / Q000008:administration & dosage / Q000737:chemistry / Q000633:toxicity*; D004625:Embryo, Nonmammalian / Q000187:drug effects; D005260:Female; D006651:Histocytochemistry; D007527:Isoenzymes / Q000378:metabolism; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism; D008840:Microfilament Proteins / Q000378:metabolism; D053758:Nanoparticles / Q000008:administration & dosage / Q000737:chemistry / Q000633:toxicity*; D020556:Neutrophil Infiltration / Q000187:drug effects; D012822:Silicon Dioxide / Q000008:administration & dosage / Q000737:chemistry / Q000633:toxicity*; D000071681:Tartrate-Resistant Acid Phosphatase; D014018:Tissue Distribution; D015027:Zebrafish
chemical_list: D004337:Drug Carriers; D007527:Isoenzymes; D008562:Membrane Glycoproteins; D008840:Microfilament Proteins; C026742:plastin; D012822:Silicon Dioxide; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase