A system for precisely targeting "out-of-control" immune cells - without interfering with correctly functioning immune cells - has been developed using nanoparticles.
Nanoparticle research is currently described as being the most studied branch of science.
Nanoparticles - tiny objects that behave as a whole unit in terms of their transport and properties - have applications in all kinds of medical fields.
They have been used as delivery systems for drugs and genes, for detecting disease or proteins, in tissue engineering and for destroying tumors, among other things.
Researchers at the University of Illinois at Chicago have now made nanoparticles from tiny pieces of protein that bind to a type of immune cell responsible for acute and chronic inflammatory responses.
'Pile-ups' of neutrophils contribute to inflammation
These cells - called neutrophils - should normally accumulate at an injury in a damaged blood vessel to prevent bacteria or bits of injured tissue from causing infection. But in chronic inflammation, these neutrophils pile up at the location of the injury, sticking to the walls of the blood vessel and damaging tissue.
The researchers made nanoparticles from tiny pieces of protein that bind to a type of immune cell responsible for acute and chronic inflammatory responses.
These pile-ups can be especially dangerous in lung injuries, where they can lead to severe breathing problems. Up to 50% of patients with this inflammation in the lungs die if it goes untreated.
The existing treatments for this - corticosteroids and non-steroidal anti-inflammatory drugs - are described by Prof. Asrar B. Malik, lead author of the new study, as "blunt instruments that affect the whole body and carry some significant side effects."
Prof. Malik and his colleagues designed a nanoparticle that could bind to the inflammation-causing neutrophils' unique receptors and armed it with an anti-inflammatory drug.
Prof. Malik explains:
"The nanoparticle is very much like a Trojan horse. 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."
Nanoparticles only target 'out-of-control' neutrophils
Testing their nanoparticles in mice with induced vascular inflammation, Prof. Malik and his colleagues used a fluorescent dye to track the particles' progress.
They observed that the nanoparticles would bind to and enter the clustering neutrophils but would not bind to any neutrophils circulating freely within the bloodstream.
When the nanoparticles were loaded with piceatannol - a drug that disrupts the adhesion of cells - the clustered neutrophils would detach from each other and the wall of the blood vessel, reducing inflammation.
Prof. Malik says that the team's findings, which are published in the journal Nature Nanotechnology, "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."
Recently, Medical News Today reported on research from the University of Texas and the University of Monterrey in Mexico examining the use of silver nanoparticles to prevent transmission of human immunodeficiency virus (HIV).