title: Imaging Functional Nucleic Acid Delivery to Skin.
abstract: Monogenic skin diseases arise from well-defined single gene mutations, and in some cases a single point mutation. As the target cells are superficial, these diseases are ideally suited for treatment by nucleic acid-based therapies as well as monitoring through a variety of noninvasive imaging technologies. Despite the accessibility of the skin, there remain formidable barriers for functional delivery of nucleic acids to the target cells within the dermis and epidermis. These barriers include the stratum corneum and the layered structure of the skin, as well as more locally, the cellular, endosomal and nuclear membranes. A wide range of technologies for traversing these barriers has been described and moderate success has been reported for several approaches. The lessons learned from these studies include the need for combinations of approaches to facilitate nucleic acid delivery across these skin barriers and then functional delivery across the cellular and nuclear membranes for expression (e.g., reporter genes, DNA oligonucleotides or shRNA) or into the cytoplasm for regulation (e.g., siRNA, miRNA, antisense oligos). The tools for topical delivery that have been evaluated include chemical, physical and electrical methods, and the development and testing of each of these approaches has been greatly enabled by imaging tools. These techniques allow delivery and real time monitoring of reporter genes, therapeutic nucleic acids and also triplex nucleic acids for gene editing. Optical imaging is comprised of a number of modalities based on properties of light-tissue interaction (e.g., scattering, autofluorescence, and reflectance), the interaction of light with specific molecules (e.g., absorbtion, fluorescence), or enzymatic reactions that produce light (bioluminescence). Optical imaging technologies operate over a range of scales from macroscopic to microscopic and if necessary, nanoscopic, and thus can be used to assess nucleic acid delivery to organs, regions, cells and even subcellular structures. Here we describe the animal models, reporter genes, imaging approaches and general strategies for delivery of nucleic acids to cells in the skin for local expression (e.g., plasmid DNA) or gene silencing (e.g., siRNA) with the intent of developing nucleic acid-based therapies to treat diseases of the skin.
authors.affiliation: TransDerm Inc., 2161 Delaware Ave, Santa Cruz, CA, 95060, USA. Roger.Kaspar@TransDermInc.com.
authors.forename: Roger L
authors.initials: RL
authors.lastname: Kaspar
authors.affiliation: Centre for Dermatology and Genetic Medicine, University of Dundee, Dundee, UK.
authors.forename: Robyn P
authors.initials: RP
authors.lastname: Hickerson
authors.affiliation: Canvax Biotech S.L., Technological Park, Cordoba, Spain.
authors.forename: Emilio
authors.initials: E
authors.lastname: González-González
authors.affiliation: TransDerm Inc., 2161 Delaware Ave, Santa Cruz, CA, 95060, USA.
authors.forename: Manuel A
authors.initials: MA
authors.lastname: Flores
authors.affiliation: TransDerm Inc., 2161 Delaware Ave, Santa Cruz, CA, 95060, USA.
authors.forename: Tycho P
authors.initials: TP
authors.lastname: Speaker
authors.affiliation: Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT, USA.
authors.forename: Faye A
authors.initials: FA
authors.lastname: Rogers
authors.affiliation: Department of Dermatology, Yale University School of Medicine, New Haven, CT, USA.
authors.forename: Leonard M
authors.initials: LM
authors.lastname: Milstone
authors.affiliation: Molecular Imaging Program at Stanford (MIPS), E150 Clark Center, Stanford University School of Medicine, 318 Campus Drive, Stanford, CA, 94305, USA. ccontag@stanford.edu.|Department of Pediatrics, E150 Clark Center, Stanford University School of Medicine, 318 Campus Drive, Stanford, CA, 94305, USA. ccontag@stanford.edu.|Department of Radiology, E150 Clark Center, Stanford University School of Medicine, 318 Campus Drive, Stanford, CA, 94305, USA. ccontag@stanford.edu.|Microbiology and Immunology, E150 Clark Center, Stanford University School of Medicine, 318 Campus Drive, Stanford, CA, 94305, USA. ccontag@stanford.edu.
authors.forename: Christopher H
authors.initials: CH
authors.lastname: Contag
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D015870:Gene Expression; D018014:Gene Transfer Techniques; D017930:Genes, Reporter; D030342:Genetic Diseases, Inborn / Q000235:genetics / Q000628:therapy; D006801:Humans; D008163:Luminescent Measurements / Q000379:methods; D051379:Mice; D008822:Mice, Transgenic; D008853:Microscopy / Q000379:methods; D057054:Molecular Imaging / Q000379:methods*; D009696:Nucleic Acids / Q000235:genetics*; D010957:Plasmids / Q000008:administration & dosage / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics; D012867:Skin / Q000378:metabolism*; D012871:Skin Diseases / Q000235:genetics / Q000628:therapy
chemical_list: D009696:Nucleic Acids; D034741:RNA, Small Interfering
keywords: Bioluminescence; Biophotonic; Fluorescence; GFP; Gene therapy; Keratin; Monogenic; Nucleic acid; Optical imaging; Pachyonychia congenita; Skin; Topical delivery; siRNA