Abstract
Background
Non‐viral methods of gene delivery have been an attractive alternative to virus‐based gene therapy. However, the vectors that are currently available have drawbacks limiting their therapeutic application.
Methods
We have developed a self‐assembled non‐viral gene carrier, poly‐L‐lysine modified iron oxide nanoparticles (IONP‐PLL), which is formed by modifying poly‐L‐lysine to the surface of iron oxide nanoparticles. The ability of IONP‐PLL to bind DNA was determined by ratio‐dependent retardation of DNA in the agarose gel and co‐sedimentation assay. In vitro cytotoxic effects were quantified by MTT assay. The transfection efficiency in vitro was evaluated by delivering exogenous DNA to different cell lines using IONP‐PLL. Intravenous injection of IONP‐PLL/DNA complexes into mice was evaluated as a gene delivery system for gene therapy. The PGL2‐control gene encoding firefly luciferase and the EGFP‐C2 gene encoding green fluorescent protein were used as marker genes.
Results
IONP‐PLL could bind and protect DNA. In contrast to PLL and cationic liposomes, IONP‐PLL described here was less cytotoxic in a broad range of concentrations. In the current study, we have demonstrated that IONP‐PLL can deliver exogenous gene to cells in vitro and in vivo. After intravenous injection, IONP‐PLL transferred reporter gene EGFP‐C2 to lung, brain, spleen and kidney. Furthermore, we have demonstrated that IONP‐PLL transferred exogenous DNA across the blood‐brain barrier to the glial cells and neuron of brain.
Conclusions
IONP‐PLL, a low‐toxicity vector, appears to have potential for fundamental research and genetic therapy in vitro and in vivo, especially for gene therapy of CNS disease. Copyright © 2003 John Wiley & Sons, Ltd.