Abstract
Purpose. The purpose of this study was the design of a polymeric platform for effective gene delivery using DNA-loaded nanoparticles.
Methods. The polymers were synthesized by carbonyldiimidazole (CDI)-mediated coupling of diamines diethylaminopropylamine (DEAPA), dimethlyaminopropylamine (DMAPA) or diethylaminoethylamine (DEAEA) to poly(vinyl alcohol) (PVA) with subsequent grafting of d,l-lactide and glycolide (1:1) in the stoichiometric ratios of 1:10 and 1:20 (free hydroxyl groups/monomer units). The polymers were characterized by 1H-NMR, gel permeation chromatography-multiple-angle laser-light-scattering, and differential scanning calorimetry. DNA-loaded nanoparticles prepared by a modified solvent displacement method were characterized with regard to their zeta (ζ)-potential and size. The transfection efficiency was assessed with the plasmid DNA pCMV-luc in L929 mouse fibroblasts.
Results. The polymers were composed of highly branched, biodegradable cationic polyesters exhibiting amphiphilic properties. The amine modification enhanced the rapid polymer degradation and resulted in the interaction with DNA during particle preparation. The nanoparticles exhibited positive ζ-potentials up to +42 mV and high transfection efficiencies, comparable to polyethlyenimine (PEI) 25kDa/DNA complexes at a nitrogen to phosphate ratio of 5.
Conclusions. The polymers combined amine-functions and short poly(D,L-lactic-co-glycolic acid) (PLGA) chains resulting in water-insoluble polymers capable of forming biodegradable DNA nanoparticles through coulombic interactions and polyester precipitation in aqueous medium. The high transfection efficiency was based on fast polymer degradation and the conservation of DNA bioactivity.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
M. A. Liu. DNA vaccines: a review. J. Intern. Med. 253:402-410 (2003).
G. Otten, M. Schaefer, C. Greer, M. Calderon-Cacia, D. Coit, J. Kazzaz, A. Medina-Selby, M. Selby, M. Singh, M. Ugozzoli, J. zur Megede, S. W. Barnett, D. O’Hagan, J. Donnelly, and J. Ulmer. Induction of broad and potent anti-human immunodeficiency virus immune responses in rhesus macaques by priming with a DNA vaccine and boosting with protein-adsorbed polylactide coglycolide microparticles. J. Virol. 77:6087-6092 (2003).
E. Walter, K. Moelling, J. Pavlovic, and H. P. Merkle. Microencapsulation of DNA using poly(DL-lactide-co-glycolide): stability issues and release characteristics. J. Control. Rel. 61:361-374 (1999).
A. M. Tinsley-Bown, R. Fretwell, A. B. Dowsett, S. L. Davis, and G. H. Farrar. Formulation of poly(D,L-lactic-co-glycolic acid) microparticles for rapid plasmid DNA delivery. J. Control. Rel. 66:229-241 (2000).
S. Ando, D. Putnam, D. W. Pack, and R. Langer. PLGA microspheres containing plasmid DNA: preservation of supercoiled DNA via cryopreparation and carbohydrate stabilization. J. Pharm. Sci. 88:126-130 (1999).
R. K. Evans, Z. Xu, K. E. Bohannon, B. Wang, M. W. Bruner, and D. B. Volkin. Evaluation of degradation pathways for plasmid DNA in pharmaceutical formulations via accelerated stability studies. J. Pharm. Sci. 89:76-87 (2000).
M. Wittmar, F. Unger, A. K. Schaper, and T. Kissel. Fast degrading, high-molecular weight, brush-like branched, amine-modified poly(vinyl alcohol)-graft-poly(D,L-lactide-co-glycolide)s as platform for parenteral drug delivery systems: Synthesis, characterization and degradation behavior. Macromolecules.
A. Breitenbach, Y. X. Li, and T. Kissel. Branched biodegradable polyesters for parenteral drug delivery systems. J. Control. Rel. 64:167-178 (2000).
T. Jung, W. Kamm, A. Breitenbach, G. Klebe, and T. Kissel. Loading of tetanus toxoid to biodegradable nanoparticles from branched poly(sulfobutyl-polyvinyl alcohol)-g-(lactide-co-glycolide) nanoparticles by protein adsorption: a mechanistic study. Pharm. Res. 19:1105-1113 (2002).
K. Kunath, A. von Harpe, D. Fischer, H. Petersen, U. Bickel, K. Voigt, and T. Kissel. Low-molecular-weight polyethylenimine as a non-viral vector for DNA delivery: comparison of physicochemical properties, transfection efficiency and in vivo distribution with high-molecular-weight polyethylenimine. J. Control. Rel. 89:113-125 (2003).
J. H. Jeong and T. G. Park. Poly(L-lysine)-g-poly(D,L-lactic-co-glycolic acid) micelles for low cytotoxic biodegradable gene delivery carriers. J. Control. Rel. 82:159-166 (2002).
D. Putnam, C. A. Gentry, D. W. Pack, and R. Langer. Polymer-based gene delivery with low cytotoxicity by a unique balance of side-chain termini. Proc. Natl. Acad. Sci. USA 98:1200-1205 (2001).
N. D. Sonawane, F. C. SzokaJr., and A. S. Verkman. Chloride accumulation and swelling in endosomes enhances DNA transfer by polyamine-DNA polyplexes. J. Biol. Chem. 278:44826-44831 (2003).
M. Koping-Hoggard, I. Tubulekas, H. Guan, K. Edwards, M. Nilsson, K. M. Varum, and P. Artursson. Chitosan as a nonviral gene delivery system. Structure-property relationships and characteristics compared with polyethylenimine in vitro and after lung administration in vivo. Gene Ther. 8:1108-1121 (2001).
N. Murthy, J. R. Robichaud, D. A. Tirrell, P. S. Stayton, and A. S. Hoffman. The design and synthesis of polymers for eukaryotic membrane disruption. J. Control. Rel. 61:137-143 (1999).
T. Ishii, Y. Okahata, and T. Sato. Mechanism of cell transfection with plasmid/chitosan complexes. Biochim. Biophys. Acta 1514:51-64 (2001).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Oster, C.G., Wittmar, M., Unger, F. et al. Design of Amine-Modified Graft Polyesters for Effective Gene Delivery Using DNA-Loaded Nanoparticles. Pharm Res 21, 927–931 (2004). https://doi.org/10.1023/B:PHAM.0000029279.50733.55
Issue Date:
DOI: https://doi.org/10.1023/B:PHAM.0000029279.50733.55