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Journal of Nanomaterials
Volume 2011 (2011), Article ID 952060, 9 pages
http://dx.doi.org/10.1155/2011/952060
Research Article

Characterization of Plasmid DNA Location within Chitosan/PLGA/pDNA Nanoparticle Complexes Designed for Gene Delivery

1Biological and Agricultural Engineering Department, Louisiana State University Agricultural Center, Rm. 149 E.B. Doran Bldg., Baton Rouge, LA 70803, USA
2Nanotechnology Center, Applied Science Department, University of Arkansas at Little Rock, Little Rock, AR 72211, USA

Received 2 June 2010; Accepted 25 July 2010

Academic Editor: Lu Sun

Copyright © 2011 Hali Bordelon et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Poly(D,L-lactide-co-glycolide-) (PLGA-)chitosan nanoparticles are becoming an increasingly common choice for the delivery of nucleic acids to cells for various genetic manipulation techniques. These particles are biocompatible, with tunable size and surface properties, possessing an overall positive charge that promotes complex formation with negatively charged nucleic acids. This study examines properties of the PLGA-chitosan nanoparticle/plasmid DNA complex after formation. Specifically, the study aims to determine the optimal ratio of plasmid DNA:nanoparticles for nucleic acid delivery purposes and to elucidate the location of the pDNA within these complexes. Such characterization will be necessary for the adoption of these formulations in a clinical setting. The ability of PLGA-chitosan nanoparticles to form complexes with pDNA was evaluated by using the fluorescent intercalating due OliGreen to label free plasmid DNA. By monitoring the fluorescence at different plasmid: nanoparticle ratios, the ideal plasmid:nanoparticle ration for complete complexation of plasmid was determined to be 1:50. Surface-Enhanced Raman Spectroscopy and gel digest studies suggested that even at these optimal complexation ratios, a portion of the plasmid DNA was located on the outer complex surface. This knowledge will facilitate future investigations into the functionality of the system in vitro and in vivo.