Nanoparticles can activate immune cells, treat diseases

Scientists have developed a new system that can precisely deliver anti-inflammatory drugs to immune cells gone out of control, while sparing their well-behaved counterparts.

The findings by researchers at the University of Illinois at Chicago were published online Feb 23 in Nature Nanotechnology.

The system uses nanoparticles made of tiny bits of protein designed to bind to unique receptors found only on neutrophils, a type of immune cell engaged in detrimental acute and chronic inflammatory responses.

In a normal immune response, neutrophils circulating in the blood respond to signals given off by injured or damaged blood vessels and begin to accumulate at the injury, where they engulf bacteria or debris from injured tissue that might cause infection.

In chronic inflammation, neutrophils can pile up at the site of injury, sticking to the blood vessel walls and to each other and contributing to tissue damage, reported Science Daily.

Corticosteroids and non-steroidal anti-inflammatory drugs used to treat inflammatory diseases are "blunt instruments that affect the whole body and carry some significant side effects", said Asrar B. Malik, Schweppe Family Distinguished Professor and head of pharmacology in the UIC College of Medicine.

Malik is also lead author of the paper.

"The nanoparticle is very much like a Trojan horse," Malik said. "It binds to a receptor found only on these activated, sticky neutrophils, and the cell automatically engulfs whatever binds there. Because circulating neutrophils lack these receptors, the system is incredibly precise and targets only those immune cells that are actively contributing to inflammatory disease."

Malik said, the findings "show that nanoparticles can be used to deliver drugs in a highly targeted, specific fashion to activated immune cells and could be designed to treat a broad range of inflammatory diseases".