A team at Yale University have used incredibly small plastic particles to smuggle therapies into cells. Their paper, published this week in Nature Materials, has possible implications for the treatment of HIV.
Small interfering RNA (siRNA) molecules have proved effective at stopping the HIV virus from reproducing in animal models. They can inactivate genes in the cells that HIV infects, so the virus is unable to enter these cells and spread. Lead author Kim Woodrow explains how the aim of this study was to produce a way of delivering these particles using nano sized plastic beads that was “safe and effective, and much easier than getting an injection of vaccine”.
To investigate whether the nanotechnology approach would work, they used an siRNA which inactivates the production of a green fluorescent protein. They then packaged the siRNAs into the plastic nanoparticles, and administered them into the vaginas of mice engineered to produce these fluorescent proteins. This gave them an easy way to track how well the delivery system worked, by simply checking the level and location of fluorescence.
The nanoparticles successfully penetrated the cells below the surface of the vaginal wall, spread through the reproductive system, and remained effective for up to 14 days. Crucially, the mice did not show signs of irritation, where as mice given the treatment by a traditional method did.
The results indicate that this method of delivery could be used to produce a topical cream containing the siRNA’s to prevent the HIV virus spreading from the source. However, the team have yet to test this method against an actual virus. Senior author E. Mark Salzman is hopeful though, and is planning ahead. He said “our next step in research will be to test this approach directly in disease models – for example in the HIV model mice.”