title: Oral gene delivery: design of polymeric carrier systems shielding toward intestinal enzymatic attack.
abstract: The gastrointestinal tract poses a variety of morphological and physiological barriers to the expression of target genes. The aim of this study was to evaluate the stability of cationic polymer/pDNA nanoparticles toward salts and enzymes of the intestinal fluid. Within this study, a chitosan-enzyme inhibitor conjugate has been generated and characterized. Based on this conjugate, nanoparticles with pDNA were generated to enhance transfection rate in oral gene delivery. The enzyme inhibitor aurintricarboxylic acid (ATA) was covalently bound to chitosan to improve the enzymatic stability of nanoparticles formed with this polymer and pDNA. Chitosan-ATA/pDNA nanoparticles showed a size of 98.5 +/- 26 nm and a zeta potential of -13.26 +/- 0.24 mV (n = 3-4). Stability studies with salt solution, lysozyme, DNase, and freshly collected porcine intestinal fluid showed that chitosan-ATA/pDNA nanoparticles are significantly (p < 0.05) more stable than unmodified chitosan/pDNA nanoparticles. Apart from improved stability, chitosan-ATA/pDNA nanoparticles showed a 2.6-fold higher transfection rate than chitosan/pDNA nanoparticles in the Caco-2 cell line, thus creating a promising carrier for orally administered therapeutic genes.
authors.affiliation: Department of Pharmaceutical Technology, Institute of Pharmacy, Leopold-Franzens-University of Innsbruck, Innrain 52, 6020 Innsbruck, Austria.
authors.forename: Ronny
authors.initials: R
authors.lastname: Martien
authors.forename: Brigitta
authors.initials: B
authors.lastname: Loretz
authors.forename: A B
authors.initials: AB
authors.lastname: Schnürch
mesh_terms: D000284:Administration, Oral; D001312:Aurintricarboxylic Acid / Q000737:chemistry*; D018938:Caco-2 Cells; D048271:Chitosan / Q000737:chemistry*; D004247:DNA / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics; D003850:Deoxyribonuclease I / Q000378:metabolism; D016503:Drug Delivery Systems / Q000379:methods; D004587:Electrophoresis, Agar Gel / Q000379:methods; D015870:Gene Expression / Q000235:genetics; D015316:Genetic Therapy / Q000379:methods; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007408:Intestinal Absorption; D007410:Intestinal Diseases / Q000235:genetics / Q000378:metabolism / Q000628:therapy*; D046529:Microscopy, Electron, Transmission / Q000379:methods; D015394:Molecular Structure; D009113:Muramidase / Q000378:metabolism; D049329:Nanostructures / Q000737:chemistry / Q000648:ultrastructure; D010316:Particle Size; D010957:Plasmids / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics; D014162:Transfection / Q000379:methods
chemical_list: D049452:Green Fluorescent Proteins; D001312:Aurintricarboxylic Acid; D004247:DNA; D048271:Chitosan; D003850:Deoxyribonuclease I; D009113:Muramidase