A self-assembling nanoparticle designed to target tumour cells as a virus would was unveiled today.
Viruses are extremely effective at targeting cells and delivering proteins into them. Mimicking a virus should therefore be a very useful way to deliver drugs to cancerous cells.
This morning at the American Chemical Society’s annual fall meeting in Philadelphia, Pennsylvania, Yuhong Chen presented data on a fully synthetic self-assembling virus-like nanoparticle. These particles fuse with cells “like real viruses”, notes Chen’s abstract. Chen, a chemist at the National Cancer Institute in Frederick, Maryland, gave a presentation on these particles before I arrived in the city. But earlier this week, his fellow researcher Nadya Tarasova explained some of the thinking behind them.
Tarasova, head of the Synthetic Biologics Core at the National Cancer Institute, notes that viruses are perfect delivery systems because they self-assemble and enter cells using receptors on cell surfaces.
To mimic a virus, the team used amino acids to build a molecule that resembles a known protein that spans cell membranes. In a paper in the Proceedings of the National Academy of Sciences (PNAS), the team previously described how these proteins self-assemble into spherical nanoparticles in solution. Now the team has gone further, showing that these nanoparticles can fuse with cells through receptors. By incorporating compounds into their nanoparticles that normally bind prostate tumour cells, their virus-mimic selectively targets these cells.
These nanoparticles were shown in the PNAS paper to hamper tumour growth in vivo. But the real trick is that they can be used to encapsulate drugs, meaning that a synthetic virus-like particle could be created to target cancer cells and then deliver a chemotherapy payload precisely to the tumour.
Creating virus-like nanoparticles using synthetic chemistry allows a huge degree of control over the particles’ properties such as their size and shape, says Tarasova. The team’s particles assemble with remarkable precision, and the researchers are now working on getting the nanoparticles into an animal model.
“In several respects, we outdid nature,” says Tarasova.