title: G-quartet oligonucleotide mediated delivery of proteins into photoreceptors and retinal pigment epithelium via intravitreal injection.
abstract: There is currently no available method to efficiently deliver proteins across the plasma membrane of photoreceptor or retinal pigment epithelium (RPE) cells in vivo. Thus, current clinical application of recombinant proteins in ophthalmology is limited to the use of proteins that perform their biological function extracellularly. The ability to traverse biological membranes would enable the mobilization of a significantly larger number of proteins with previously well characterized properties. Nucleolin is abundantly present on the surface of rapidly dividing cells including cancer cells. Surprisingly, nucleolin is also present on the surface of photoreceptor cell bodies. Here we investigated whether nucleolin can be utilized as a gateway for the delivery of proteins into retinal cells following intravitreal injection. AS1411 is a G-quartet aptamer capable of targeting nucleolin. Subsequent to intravitreal injection, fluorescently labeled AS1411 localized to various retinal cell types including the photoreceptors and RPE. AS1411 linked to streptavidin (a ∼50 kDa protein) via a biotin bridge enabled the uptake of Streptavidin into photoreceptors and RPE. AS1411-Streptavidin conjugate applied topically to the cornea allowed for uptake of the conjugate into the nucleus and cytoplasm of corneal endothelial cells. Clinical relevance of AS1411 as a delivery vehicle was strongly indicated by demonstration of the presence of cell surface nucleolin on the photoreceptors, inner neurons and ganglion cells of human retina. These data support exploration of AS1411 as a means of delivering therapeutic proteins to diseased retina.
authors.affiliation: Department of Ophthalmology, Program in Genetics, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA.
authors.forename: Derek
authors.initials: D
authors.lastname: Leaderer
authors.affiliation: Department of Ophthalmology, Program in Genetics, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA.
authors.forename: Siobhan M
authors.initials: SM
authors.lastname: Cashman
authors.affiliation: Department of Ophthalmology, Program in Genetics, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA. Electronic address: Rajendra.Kumar-Singh@tufts.edu.
authors.forename: Rajendra
authors.initials: R
authors.lastname: Kumar-Singh
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D052157:Aptamers, Nucleotide / Q000008:administration & dosage*; D016503:Drug Delivery Systems / Q000379:methods*; D006801:Humans; D007150:Immunohistochemistry; D058449:Intravitreal Injections; D061986:MCF-7 Cells; D051379:Mice; D008807:Mice, Inbred BALB C; D009841:Oligonucleotides / Q000008:administration & dosage* / Q000378:metabolism; D010750:Phosphoproteins / Q000378:metabolism; D020419:Photoreceptor Cells, Vertebrate / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000378:metabolism; D011994:Recombinant Proteins / Q000008:administration & dosage* / Q000378:metabolism; D055213:Retinal Pigment Epithelium / Q000378:metabolism*; D000097796:Nucleolin
chemical_list: D052157:Aptamers, Nucleotide; D009841:Oligonucleotides; D010750:Phosphoproteins; D016601:RNA-Binding Proteins; D011994:Recombinant Proteins; D000097796:Nucleolin
keywords: Aptamer; Cornea; Intravitreal; Nucleolin; Retina; Shuttle; Topical