Injections of neutrophil “nanosponges” effectively treated severe rheumatoid arthritis in two mouse models, according to engineers from the University of California – San Diego.
Injections of these nanosponges early on also helped prevent the disease from developing, the engineers suggest, in a study published recently in Nature Nanotechnology.
“Nanosponges are a new paradigm of treatment to block pathological molecules from triggering disease in the body,” said senior author Liangfang Zhang, a nanoengineering professor at the UC San Diego Jacobs School of Engineering, in a media release.
“Rather than creating treatments to block a few specific types of pathological molecules, we are developing a platform that can block a broad spectrum of them, and this way we can treat and prevent disease more effectively and efficiently.”
These nanosponges are composed of nanoparticles of biodegradable polymer coated with the cell membranes of neutrophils, a type of white blood cell, the release explains.
Neutrophils are among the immune system’s first responders against invading pathogens. They are also known to play a role in the development of rheumatoid arthritis.
When rheumatoid arthritis develops, cells in the joints produce inflammatory proteins called cytokines. Release of cytokines signals neutrophils to enter the joints. Once there, cytokines bind to receptors on the neutrophil surfaces, activating them to release more cytokines, which in turn draws more neutrophils to the joints and so on.
The nanosponges essentially nip this inflammatory cascade in the bud. By acting as tiny neutrophil decoys, they intercept cytokines and stop them from signaling even more neutrophils to the joints, reducing inflammation and joint damage, the release explains.
These nanosponges may offer a promising alternative to current treatments for rheumatoid arthritis, the researchers suggest.
“Neutralizing just one or two types might not be as effective. So our approach is to take neutrophil cell membranes, which naturally have receptors to bind all these different types of cytokines, and use them to manage an entire population of inflammatory molecules,” Zhang says.
“This strategy removes the need to identify specific cytokines or inflammatory signals in the process. Using entire neutrophil cell membranes, we’re cutting off all these inflammatory signals at once,” said first author Qiangzhe Zhang, a PhD student in Professor Liangfang Zhang’s research group at UC San Diego.
In mouse models of severe rheumatoid arthritis, injecting nanosponges in inflamed joints led to reduced swelling and protected cartilage from further damage. The nanosponges performed just as well as treatments in which mice were administered a high dose of monoclonal antibodies.
The nanosponges also worked as a preventive treatment when administered prior to inducing the disease in another group of mice, the release adds.
Professor Liangfang Zhang cautions that the nanosponge treatment does not eliminate the disease. “We are basically able to manage the disease. It’s not completely gone. But swelling is greatly reduced and cartilage damage is minimized,” he said.
The team hopes to one day see their work in clinical trials, the release concludes.
[Source(s): University of California – San Diego, Science Daily]