title: Cell-penetrating self-nanoemulsifying drug delivery systems (SNEDDS) for oral gene delivery.
abstract: OBJECTIVE
  The aim of study was to investigate whether cell-penetrating peptides could amplify cellular uptake of plasmid DNA (pDNA) loaded self-nanoemulsifying drug delivery systems (SNEDDS) by mucosal epithelial cells, thereby enhancing transfection efficiency.
  
  
  METHODS
  HIV-1 Tat peptide-oleoyl conjugate (TAT-OL) was synthesized through amide bond formation between HIV-1 Tat-protein 49-57 (TAT) and oleoyl-chloride (OL). SNEDDS formulation contained 29.7% each of Cremophor EL, Capmul MCM and Crodamol, 9.9% propylene glycol and 1% TAT-OL. SNEDDS with OL instead of TAT-OL served as control.
  
  
  RESULTS
  Fluorescent-microscopy demonstrated 0.5% (m/v) nanoemulsions were suitable for subsequent studies. Mucus diffusion of nanoemulsion loaded with fluorescein diacetate (FDA) was 1.5-fold increased by incorporation of TAT-OL. Confocal microscopy confirmed that droplets of nanoemulsions were successfully internalized. Furthermore, quantitative analysis showed that addition of TAT-OL increases uptake of nanoemulsions by 2.3- and 2.6-folds after 2 and 4 hours of incubation, respectively. Cellular internalization pathways were found with substantial decrease in uptake in presence of indomethacin and chlorpromazine. Transfection efficiency investigated on HEK-293-cells was found to be 1.7- and 1.8-fold higher for SNEDDS loaded with TAT-OL compared to Lipofectin and control, respectively.
  
  
  CONCLUSIONS
  In comparison to prevailing lipid and polymer-based delivery systems, these novel cell-penetrating SNEDDS likely represent most effective, simplistic and expedite dosage form for mucosal gene delivery.
authors.affiliation: a Center for Chemistry and Biomedicine, Department of Pharmaceutical Technology, Institute of Pharmacy , University of Innsbruck , Innsbruck , Austria.
authors.forename: Arshad
authors.initials: A
authors.lastname: Mahmood
authors.affiliation: a Center for Chemistry and Biomedicine, Department of Pharmaceutical Technology, Institute of Pharmacy , University of Innsbruck , Innsbruck , Austria.
authors.forename: Felix
authors.initials: F
authors.lastname: Prüfert
authors.affiliation: a Center for Chemistry and Biomedicine, Department of Pharmaceutical Technology, Institute of Pharmacy , University of Innsbruck , Innsbruck , Austria.
authors.forename: Nuri Ari
authors.initials: NA
authors.lastname: Efiana
authors.affiliation: b Daniel Swarovski Research Laboratory, Department of Visceral, Transplant and Thoracic Surgery , Medical University Innsbruck , Innsbruck , Austria.|c Department for General, Visceral and Transplantation Surgery , Campus Virchow-Klinikum, Charité Universitätsmedizin , Berlin , Germany.
authors.forename: Muhammad Imtiaz
authors.initials: MI
authors.lastname: Ashraf
authors.affiliation: d Department of Anesthesiology and Critical Care Medicine , Medical University Innsbruck , Innsbruck , Austria.
authors.forename: Martin
authors.initials: M
authors.lastname: Hermann
authors.affiliation: e Institute of Analytical Chemistry and Radiochemistry , University of Innsbruck , Innsbruck , Austria.
authors.forename: Shah
authors.initials: S
authors.lastname: Hussain
authors.affiliation: a Center for Chemistry and Biomedicine, Department of Pharmaceutical Technology, Institute of Pharmacy , University of Innsbruck , Innsbruck , Austria.
authors.forename: Andreas
authors.initials: A
authors.lastname: Bernkop-Schnürch
mesh_terms: D000284:Administration, Oral; D057846:Cell-Penetrating Peptides / Q000378:metabolism*; D002626:Chemistry, Pharmaceutical; D016503:Drug Delivery Systems; D004655:Emulsions; D015316:Genetic Therapy / Q000379:methods*; D057809:HEK293 Cells; D006801:Humans; D008055:Lipids; D014162:Transfection
chemical_list: D057846:Cell-Penetrating Peptides; D004655:Emulsions; D008055:Lipids
keywords: Cell-penetrating peptide; HIV-1 Tat protein; SNEDDS; cellular internalization; transfection efficiency