title: Development of an efficient transdermal delivery system of small interfering RNA using functional peptides, Tat and AT-1002.
abstract: Topical use of small interfering RNA (siRNA) as a therapeutic nucleic acid is increasingly studied for the treatment of skin diseases and for the improvement of skin properties. However, naked siRNA transdermal delivery is limited by its low stability in the body and low permeability into target cells. This is due to various skin barriers such as the stratum corneum that has multiple lipid bilayers and epidermal layers that have tight junctions. In this study, we investigate non-invasive transdermal siRNA delivery using two functional peptides: AT1002, which is a tight junction modulator and 6-mer synthetic peptide belonging to a novel class of compounds that reversibly increases paracellular transport of molecules across the epithelial barrier; and Tat, which is a cell-penetrating peptide applicable as a transdermal siRNA delivery enhancer. We examined whether expression of the tight junction protein zonula occludens protein 1 (ZO-1) was detected in mouse skin applied with AT1002. Additionally, siRNA stabilities for RNaseA using Tat and AT1002 were assessed. We also determined the intradermal delivery efficiency of siRNA using functional peptides by confocal laser microscopy of fluorescently labeled siRNA in mouse skin. We found that the Tat analog and AT1002 strongly increased siRNA stability against RNaseA. In addition, ZO-1 disappeared from the skin after treatment with AT1002, yet recovered with time after washing. Finally, we also found that Tat and AT1002 peptides accelerate transdermal siRNA delivery both widely and effectively. Thus, combination of Tat and AT1002 is expected to be a transdermal delivery enhancer of siRNA.
authors.affiliation: Laboratory of Pharmaceutics and Drug Delivery, Department of Pharmaceutical Science, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, Japan.
authors.forename: Tamae
authors.initials: T
authors.lastname: Uchida
authors.forename: Takanori
authors.initials: T
authors.lastname: Kanazawa
authors.forename: Yuuki
authors.initials: Y
authors.lastname: Takashima
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Okada
mesh_terms: D000279:Administration, Cutaneous; D000818:Animals; D002460:Cell Line; D016503:Drug Delivery Systems / Q000379:methods*; D005260:Female; D015603:Keratinocytes / Q000187:drug effects / Q000378:metabolism; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009842:Oligopeptides / Q000008:administration & dosage* / Q000378:metabolism; D010446:Peptide Fragments / Q000008:administration & dosage* / Q000378:metabolism; D034741:RNA, Small Interfering / Q000008:administration & dosage* / Q000378:metabolism; D054322:tat Gene Products, Human Immunodeficiency Virus / Q000008:administration & dosage* / Q000378:metabolism
chemical_list: C530561:AT1002; D009842:Oligopeptides; D010446:Peptide Fragments; D034741:RNA, Small Interfering; D054322:tat Gene Products, Human Immunodeficiency Virus; C520542:tat peptide (48-57), Human immunodeficiency virus 1