title: Decationized polyplexes as stable and safe carrier systems for improved biodistribution in systemic gene therapy.
abstract: Many polycation-based gene delivery vectors show high transfection in vitro, but their cationic nature generally leads to significant toxicity and poor in vivo performance which significantly hampers their clinical applicability. Unlike conventional polycation-based systems, decationized polyplexes are based on hydrophilic and neutral polymers. They are obtained by a 3-step process: charge-driven condensation followed by disulfide crosslinking stabilization and finally polyplex decationization. They consist of a disulfide-crosslinked poly(hydroxypropyl methacrylamide) (pHPMA) core stably entrapping plasmid DNA (pDNA), surrounded by a shell of poly(ethylene glycol) (PEG). In the present paper the applicability of decationized polyplexes for systemic administration was evaluated. Cy5-labeled decationized polyplexes were evaluated for stability in plasma by fluorescence single particle tracking (fSPT), which technique showed stable size distribution for 48 h unlike its cationic counterpart. Upon the incubation of the polymers used for the formation of polyplexes with HUVEC cells, MTT assay showed excellent cytocompatibility of the neutral polymers. The safety was further demonstrated by a remarkable low teratogenicity and mortality activity of the polymers in a zebrafish assay, in great contrast with their cationic counterpart. Near infrared (NIR) dye-labeled polyplexes were evaluated for biodistribution and tumor accumulation by noninvasive optical imaging when administered systemically in tumor bearing mice. Decationized polyplexes exhibited an increased circulation time and higher tumor accumulation, when compared to their cationic precursors. Histology of tumors sections showed that decationized polyplexes induced reporter transgene expression in vivo. In conclusion, decationized polyplexes are a platform for safer polymeric vectors with improved biodistribution properties when systemically administered.
authors.affiliation: Department of Pharmaceutics, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, 3584 CG Utrecht, The Netherlands.
authors.forename: Luís
authors.initials: L
authors.lastname: Novo
authors.affiliation: Nanomedicines and Theranostics, Department for Experimental Molecular Imaging, University Hospital RWTH Aachen, Pauwelsstrasse 30, 52074 Aachen, Germany.
authors.forename: Larissa Y
authors.initials: LY
authors.lastname: Rizzo
authors.affiliation: Nanomedicines and Theranostics, Department for Experimental Molecular Imaging, University Hospital RWTH Aachen, Pauwelsstrasse 30, 52074 Aachen, Germany.
authors.forename: Susanne K
authors.initials: SK
authors.lastname: Golombek
authors.affiliation: Laboratory for General Biochemistry and Physical Pharmacy, Faculty of Pharmacy, Ghent University, Ghent Research Group on Nanomedicines, Harelbekestraat 72, 9000 Ghent, Belgium.
authors.forename: George R
authors.initials: GR
authors.lastname: Dakwar
authors.affiliation: Department of Pharmaceutics, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, 3584 CG Utrecht, The Netherlands.
authors.forename: Bo
authors.initials: B
authors.lastname: Lou
authors.affiliation: Laboratory for General Biochemistry and Physical Pharmacy, Faculty of Pharmacy, Ghent University, Ghent Research Group on Nanomedicines, Harelbekestraat 72, 9000 Ghent, Belgium.
authors.forename: Katrien
authors.initials: K
authors.lastname: Remaut
authors.affiliation: Department of Pharmaceutics, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, 3584 CG Utrecht, The Netherlands.
authors.forename: Enrico
authors.initials: E
authors.lastname: Mastrobattista
authors.affiliation: Department of Pharmaceutics, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, 3584 CG Utrecht, The Netherlands.
authors.forename: Cornelus F
authors.initials: CF
authors.lastname: van Nostrum
authors.affiliation: Helmholtz Institute for Biomedical Engineering, Biointerface Laboratory, RWTH Aachen University, Aachen, Germany.
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Jahnen-Dechent
authors.affiliation: Nanomedicines and Theranostics, Department for Experimental Molecular Imaging, University Hospital RWTH Aachen, Pauwelsstrasse 30, 52074 Aachen, Germany.
authors.forename: Fabian
authors.initials: F
authors.lastname: Kiessling
authors.affiliation: Laboratory for General Biochemistry and Physical Pharmacy, Faculty of Pharmacy, Ghent University, Ghent Research Group on Nanomedicines, Harelbekestraat 72, 9000 Ghent, Belgium.|Centre for Nano- and Biophotonics, Ghent University, Harelbekestraat 72, 9000 Ghent, Belgium.
authors.forename: Kevin
authors.initials: K
authors.lastname: Braeckmans
authors.affiliation: Department of Pharmaceutics, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, 3584 CG Utrecht, The Netherlands.|Nanomedicines and Theranostics, Department for Experimental Molecular Imaging, University Hospital RWTH Aachen, Pauwelsstrasse 30, 52074 Aachen, Germany.|Department of Targeted Therapeutics, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands.
authors.forename: Twan
authors.initials: T
authors.lastname: Lammers
authors.affiliation: Department of Pharmaceutics, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, 3584 CG Utrecht, The Netherlands.
authors.forename: Wim E
authors.initials: WE
authors.lastname: Hennink
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D004247:DNA / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics / Q000633:toxicity; D004355:Drug Stability; D004625:Embryo, Nonmammalian / Q000187:drug effects; D005260:Female; D018014:Gene Transfer Techniques; D049452:Green Fluorescent Proteins / Q000235:genetics; D061307:Human Umbilical Vein Endothelial Cells / Q000187:drug effects; D006801:Humans; D008819:Mice, Nude; D009369:Neoplasms / Q000378:metabolism*; D010316:Particle Size; D010957:Plasmids; D011108:Polymers / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics / Q000633:toxicity; D014018:Tissue Distribution; D015027:Zebrafish / Q000196:embryology
chemical_list: D011108:Polymers; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D004247:DNA
keywords: Biocompatibility; Biodistribution; EPR; Gene delivery; Nanoparticle; Polymer