Nanoparticles Show Potential for Treating MS
Turning Down an Autoimmune Attack continued...
He's already tried the approach in humans using white blood cells that were first collected and then killed. He then attached proteins to the dying cells and infused them into the body. In an early safety trial, Miller says that approach appeared to be well tolerated.
"There [were no side effects], there was no re-triggering of disease, and we actually showed that immune responses in patients were decreased," Miller says.
But other immune responses, such as protection against certain infections, remained strong. That suggests that patients treated this way wouldn't see the kind of general immune suppression that happens with current treatments for autoimmune diseases.
The problem with using whole cells, however, is that it's time consuming and expensive.
So Miller wondered if it might be possible to try the same thing with synthetic nanoparticles. First they tried tiny plastic beads. But since those don't break down in the body, he asked his Northwestern colleague Lonnie Shea, PhD, who is a biomedical engineer, for help finding another material that might be safer.
They decided on poly(lactide-co-glycolide), or PLG. It's a material that's used to make sutures, grafts, and other things that are meant to slowly dissolve in the body. By first dissolving PLG and then spinning the watery solution very rapidly, they were able to make tiny particles that could carry myelin proteins.
When they infused these protein-coated particles into the mice, they were able to both prevent the development of a mouse disease that mimics MS and to stop attacks in mice that already had the disease.
"We think this is actually a simpler option. You don't have to manipulate cells and put an antigen on them. This way, you could have an off-the-shelf product," Shea says.
What's more, the nanoparticles can be coated in many different kinds of proteins, which means they could one day treat other kinds of autoimmune diseases and even problems like food allergies.
"There are just so many possible applications of this, it's fun to think about," says Shea.
First, though, the technology has to be tested in humans. Before that can happen, Miller says they need to conduct more animal trials. If all goes well, he thinks the first human studies might be two years away.