Improving cellular uptake and in vivo tumor suppression efficacy of liposomal oligonucleotides by urea as a chemical penetration enhancer
Article first published online: 25 JAN 2013
Copyright © 2012 John Wiley & Sons, Ltd.
The Journal of Gene Medicine
Volume 15, Issue 1, pages 12–19, January 2013
How to Cite
Saffari, M., Tamaddon, A. M., Shirazi, F. H., Oghabian, M. A. and Moghimi, H. R. (2013), Improving cellular uptake and in vivo tumor suppression efficacy of liposomal oligonucleotides by urea as a chemical penetration enhancer. J. Gene Med., 15: 12–19. doi: 10.1002/jgm.2688
- Issue published online: 25 JAN 2013
- Article first published online: 25 JAN 2013
- Accepted manuscript online: 27 DEC 2012 05:20AM EST
- Manuscript Accepted: 26 NOV 2012
- Manuscript Revised: 11 NOV 2012
- Manuscript Received: 9 AUG 2012
- antisense oligodeoxynucleotide;
- gene delivery;
Liposomes are among the most widely used carriers for the delivery of antisense oligonucleotides (AsODNs) to intracellular targets. Although different strategies have been employed, the question of how to improve liposomal uptake and enhance the release of AsODN into cytoplasm still remains to be answered with respect to the use of a safe, easy and economic method. In the present study, the possibility of enhancing such processes at cellular and animal levels using urea as a penetration enhancer was investigated.
To perform this investigation, a cationic liposome containing an AsODN against protein kinase (PKC)-α was prepared, and the effect of urea on its cellular internalization and the related sequence-specific inhibition of gene expression in human lung adenocarcinoma A549 cells were investigated by flow cytometry and the reverse transcriptase-polymerase chain reaction, respectively. In in vivo studies, a xenograft lung tumor was established in nude mice by A549 cells and the enhancement effect of urea toward the effects of liposomal AsODN on tumor growth was investigated.
Cellular studies revealed that urea treatment increases liposomal uptake and the release of AsODN into the cytoplasm by approximately 40%. Sequence-specific inhibition of target gene PKC-α expression was also increased by approximately two-fold by urea at 200–300 nM AsODN. In animal studies, urea significantly decreased the tumor volume (approximately 40%) and increased its doubling time from approximately 13 days to 17 days.
Urea, and possibly other membrane fluidizers, could be regarded as penetration enhancers for liposomal AsODN delivery and may improve the therapeutic effect of these gene-therapy vectors at both cellular and animal levels. Copyright © 2012 John Wiley & Sons, Ltd.