RNA interference for the treatment of cancer

RNA interference (RNAi) is the latest new technology in the field of genetic medicine in which specific genes can be turned off, or silenced, so as to affect a therapeutic outcome. It can be highly specific, works in the nanomolar range and is far more effective than the antisense approaches popular 10-15 years ago. Here we review the field and explore the potential role of RNAi in cancer therapy, highlighting recent progress and examining the hurdles that must be overcome before this promising technology is ready for clinical use. (C) 2006 Prous Science. All rights reserved

Development of a novel method for formulating stable siRNA-loaded lipid particles for In vivo use

Purpose: A simple yet novel method was developed to prepare stable PEGylated siRNA-loaded lipid particles which are suitable for in vivo use. Methods: PEGylated siRNA-loaded lipid particles were formulated by hydration of a freeze-dried matrix. The effect of various formulation parameters on the size and homogeneity of resulting particles was studied. Particles prepared using this method were compared to those prepared using an established post-insertion procedure for the entrapment efficiency, stability, in vitro biological activity as well as in vivo biodistribution. Results: Using this hydration method, a particle size of less than 200 nm can be obtained with high siRNA entrapment efficiency (>90%) and high gene-silencing efficiency. Following intravenous administration into mice, these particles achieved a similar degree of accumulation in subcutaneous tumours but displayed less liver uptake compared to the post-insertion formulations. Importantly, in contrast to post-insertion preparations, particles made by hydration method retained 100% of their gene-silencing efficiency after storage at room temperature for 1 month. Conclusions: This paper describes a simple method of formulating PEGylated siRNA-loaded lipid particles. Given the ease of preparation, long term stability and favourable characteristics for in vivo delivery, our work represents an advance in lipid formulation of siRNA for in vivo use