Nanotechnology may lead to safe, effective delivery of gene therapy

• Researchers in the US have shown that nanoparticles can be used to deliver genetic material into cells safely and effectively, potentially overcoming the primary obstacle to the development of gene therapy.
• Problems with delivery systems for genes -- often based on the use of viral vectors - have already caused researchers to pull gene therapy projects.
• This led the US Food and Drug Administration (FDA) to issue a moratorium on the conduct of all gene therapy trials using retroviruses.
• Now, scientists at the Lankenau Institute for Medical Research and Massachusetts Institute of Technology (MIT) have performed preclinical proof-of- principle studies showing how nanotechnology can be used as a non-viral approach to enhance gene therapy for cancer.
• The nanotechnology-based approach used by the researchers has minimal toxic side effects to normal cells.
• C32 works by condensing the DNA in a gene and allowing the resulting nanoparticles that are formed to enter cells through a process called endocytosis.
• The researchers used the polymer to deliver a genetically modified diphtheria toxin gene that would be produced only in prostate cells.
• When this was injected into the prostate tumours in animals, tumour growth was suppressed or reversed (in 40 per cent of cases), relative to untreated tumors.
• Dr Janet Sawicki, one of the investigators at Lankenau, said that the study showed that the C32 nanoparticles deliver DNA very efficiently to tumor cells, "C32 delivered DNA intratumorally around four-fold better than one of the best commercially available reagents, jetPEI (polyethyleneimine), and 26-fold better than naked DNA," she said.
• This feature may help safeguard the healthy tissue surrounding tumours, offering a significant improvement over currently available therapies, which tend to damage the healthy tissue near the cancer.
• In future work, the Lankenau and MIT researchers aim to expand their work to test whether this nanotechnology can be adapted for a non-radioactive type of brachytherapy, a practice that has grown in popularity to treat localised prostate cancer.