Conceal drug delivery tech to avoid immune system wrath

Drug delivery tech is often so innovative, but that can amount to nothing when the body strikes it down. If it doesn't work, then what? Case in point: The immune system can attack drug-carrying nanoparticles if they're not built right, seeing a foreign invader rather than an ally.

Researchers from the University of Copenhagen and elsewhere have figured out that the immune system plays a much larger role than previously thought in helping drug delivery technology to succeed. They've also determined that the coating engineers place on the nanoparticle surface can make all the difference. If done right, they discovered, it can free the drug delivery mechanism to do its job essentially undercover, once injected into the bloodstream. For example, they found that if they cover the nanocarrier surface with water-soluble polymers, the drug avoids triggering an immune system response.

"This makes the surface 'water-like' and less visible to the immune system," Moein Moghimi, professor of pharmaceutical sciences at the University of Copenhagen, explained in the school's release announcing the finding.

This is a simple discovery that really matters a lot. Nanoparticle drug delivery has enormous potential, as the researchers note. It can be as tiny as a virus and carry potent, concentrated, targeted treatments for diseases such as cancer. But this is still a work in progress. Scientists ideally hope to develop microscopic drug delivery treatment technology that hits its target without breaking up before it gets there. That's all a wasted effort, however, if the immune system targets the whole thing before it can perform its job. And while water-soluble polymers appear to help, engineers must not end up with something that breaks up too soon or inadvertently aims for another pathway. It seems that the surface engineering of polymeric nanoparticles can make all the difference.

What the research doesn't answer: questions or concerns about potential nanoparticle toxicity, regardless of what coating makes it invisible to the immune system.

For more details, read about the study in the "news and views" section in the journal Nature Nanotechnology.

- here's the release
- access the Nature Nanotechnology piece (sub. req.)