Researchers at the California Institute of Technology have been using small interfering RNA (siRNA), sometimes known as silencing RNA, to “silence” specific genes that are implicated in certain malignancies. One of the primary challenges associated with this type of therapy is delivering the therapeutic agent into the body and then to the tumor in a safe and effective manner.
The Caltech researchers have incorporated siRNA into nanoparticles that are formed completely by self-assembly, characterized the behavior of these nanoparticles and studied their safety and efficacy in mice.
Using extensive physicochemical and biological characterization, the investigators are able to estimate the composition of individual nanoparticles and to correlate the nanoparticle structure with its biological function. This quantitative approach provides unique insights into the design of more effective nanoparticle carriers.
According to the lead author of the study, Derek Bartlett: “Safe and effective delivery remains perhaps the greatest impediment to the clinical realization of small interfering RNA in cancer therapy. Formation of siRNA nanoparticles using cyclodextrin-containing polycations is one of the most promising strategies for systemic siRNA delivery, and such nanoparticles are expected to enter phase I clinical trials by late 2007.”