Premium
Plasmid size influences chitosan nanoparticle mediated gene transfer to chondrocytes
Author(s) -
Xu Ximing,
Capito Ramille M.,
Spector Myron
Publication year - 2007
Publication title -
journal of biomedical materials research part a
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.849
H-Index - 150
eISSN - 1552-4965
pISSN - 1549-3296
DOI - 10.1002/jbm.a.31479
Subject(s) - chitosan , plasmid , transfection , nanoparticle , materials science , biophysics , fluorescence microscope , green fluorescent protein , microbiology and biotechnology , in vitro , gene delivery , fluorescence , nanotechnology , chemistry , biology , biochemistry , dna , gene , physics , quantum mechanics
The objective of the present study was to prepare chitosan nanoparticles incorporating a relatively large plasmid encoding for osteogenic protein (OP)‐1 and to determine the ability of these nanoparticles to transfect adult canine articular chondrocytes in vitro . The positive charge of chitosan acted to condense the relatively large negatively‐charged OP‐1 plasmid such that it could be incorporated into nanoparticles. Incorporation of the plasmid into the chitosan nanoparticles did not affect the structural integrity of the plasmid as demonstrated by gel electrophoresis. The morphology and size of the nanoparticles were found to vary with the chitosan:plasmid weight ratio. Nanoparticles formulated with a chitosan:plasmid ratio of 10:1 were of uniformly small size (less than 250 nm) and spherical shape. These nanoparticles had a positive charge of about 20 mV. FITC‐labeled chitosan nanoparticles were found in virtually all of the cells after 24 h of incubation with the nanoparticles, and confocal microscopy revealed FITC‐related fluorescence in the nucleus of the chondrocytes. Although transfection of the chondrocytes was demonstrated by the fluorescence of cells treated with chitosan nanoparticles containing the plasmid for the enhanced green fluorescence protein, cells transfected with nanoparticles incorporating the larger OP‐1 plasmid did not show OP‐1 expression measured by ELISA for up to 2 weeks in culture. These results indicate that although a large plasmid can be successfully incorporated within chitosan nanoparticles, the size of the plasmid incorporated within the nanoparticles may still significantly affect gene transfer to cells. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008