title: RNAi mediated IL-6 in vitro knockdown in psoriasis skin model with topical siRNA delivery system based on liquid crystalline phase.
abstract: Gene therapy by RNA interference (RNAi) is a post-transcriptional silencing process that can suppress the expression of a particular gene and it is a promising therapeutic approach for the treatment of many severe diseases, including cutaneous disorders. However, difficulties related to administration and body distribution limit the clinical use of small interfering RNA (siRNA) molecules. In this study, we proposed to use nanocarriers to enable siRNA application in the topical treatment of skin disorders. A siRNA nanodispersion based on liquid crystalline phase and composed of monoolein (MO), oleic acid (OA) and polyethylenimine (PEI) was developed and its physicochemical properties, efficiency of complexation and carrier/siRNA stability were assessed. Subsequently, cell viability, cellular uptake, in vitro skin irritation test using reconstructed human epidermis (RHE) and in vitro IL-6 knockdown in psoriasis skin model were evaluated. The results showed that the liquid crystalline nanodispersion is a promising topical delivery system for administration of siRNA, being able to overcome the limitations of the route of administration, as well those resulting from the characteristics of siRNA molecules. The formulation was effective at complexing the siRNA, presented high rate of cell uptake (∼90%), increased the skin penetration of siRNA in vitro, and did not cause skin irritation compared with Triton-X (a moderate irritant), resulting in a 4-fold higher viability of reconstructed human epidermis and a 15.6-fold lower release of IL-1α. A single treatment with the liquid crystalline nanodispersion carrying IL-6 siRNA for 6h was able to reduce the extracellular IL-6 levels by 3.3-fold compared with control treatment in psoriasis skin model. Therefore, liquid crystalline nanodispersion is a suitable nanocarrier for siRNA with therapeutic potential to suppress skin disease-specific genes. This study also highlights the applicability of reconstructed skin models in pharmaceutical field to evaluate the performance of delivery systems without the use of animal models.
authors.affiliation: School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Av. do Café, s/n, 14040-903 Ribeirão Preto, SP, Brazil.
authors.forename: Lívia Vieira
authors.initials: LV
authors.lastname: Depieri
authors.affiliation: School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Av. do Café, s/n, 14040-903 Ribeirão Preto, SP, Brazil.
authors.forename: Lívia Neves
authors.initials: LN
authors.lastname: Borgheti-Cardoso
authors.affiliation: School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Av. do Café, s/n, 14040-903 Ribeirão Preto, SP, Brazil.
authors.forename: Patrícia Mazureki
authors.initials: PM
authors.lastname: Campos
authors.affiliation: School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Av. do Café, s/n, 14040-903 Ribeirão Preto, SP, Brazil.
authors.forename: Katia Kaori
authors.initials: KK
authors.lastname: Otaguiri
authors.affiliation: School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Av. do Café, s/n, 14040-903 Ribeirão Preto, SP, Brazil.
authors.forename: Fabiana Testa Moura de Carvalho
authors.initials: FT
authors.lastname: Vicentini
authors.affiliation: Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes, 2415, 05508-900 São Paulo, SP, Brazil; Albany College of Pharmacy and Health Sciences, 106 New Scotland Ave., Albany, New York, USA.
authors.forename: Luciana Biagini
authors.initials: LB
authors.lastname: Lopes
authors.affiliation: School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Av. do Café, s/n, 14040-903 Ribeirão Preto, SP, Brazil.
authors.forename: Maria José Vieira
authors.initials: MJ
authors.lastname: Fonseca
authors.affiliation: School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Av. do Café, s/n, 14040-903 Ribeirão Preto, SP, Brazil. Electronic address: vbentley@usp.br.
authors.forename: M Vitória Lopes Badra
authors.initials: MV
authors.lastname: Bentley
mesh_terms: D055785:Gene Knockdown Techniques; D006801:Humans; D066298:In Vitro Techniques; D015850:Interleukin-6 / Q000235:genetics*; D008954:Models, Biological; D011565:Psoriasis / Q000235:genetics*; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000008:administration & dosage*
chemical_list: D015850:Interleukin-6; D034741:RNA, Small Interfering
keywords: In vitro knockdown; Liquid crystalline nanodispersion; Reconstructed human epidermis; Skin penetration; Small interfering RNA; Topical delivery system