Macrophage-targeting nanoparticles may yield new treatments

Last Updated: 2015-04-30

By Rob Goodier

NEW YORK (Reuters Health) - Attaching dextran molecules to anti-inflammatory prodrugs creates a macrophage-seeking conjugate that may deliver more of a drug to inflamed tissues, preclinical evidence suggests.

The technique may someday yield new treatments for inflammatory disorders and diseases of the gut, the researchers said in their presentation April 21 at the American Society of Mechanical Engineering's Global Conference on Nanoengineering for Medicine and Biology in Minneapolis, Minnesota.

"Oral delivery gets only a small amount of the drug to the site. We found a mechanism that allows a huge amount to get to the inflamed tissue," Dr. Andrew Smith, assistant professor of bioengineering at the University of Illinois at Urbana-Champaign, told Reuters Health by telephone.

Dr. Smith and colleagues injected their compound into the peritoneal cavities of obese mice with type 2 diabetes and found that 40-60% of the dose distributed to inflamed fatty tissue.

Macrophages selectively take up the polysaccharide dextran and with it, the attached drug molecules. Nearly 90% of the dose that distributed to inflamed tissue was taken into macrophages, according to the researchers.

The treatment apparently subdued the macrophages and slowed or prevented their release of cytokines.

The treatment might also have reduced the number of macrophages, but so far the researchers are only speculating on that point, Dr. Smith said.

Dr. Warren Chan, an associate professor of biomaterials and biomedical engineering at the University of Toronto, in Canada, who is not involved in the research, told Reuters Health that nanoparticles like these may someday treat inflammatory disorders by delivering a large payload of drugs to inflamed tissues.

"The novelty here is that this is completely made of clinically approved materials," Dr. Smith said. He anticipates lower hurdles before taking a working formulation to clinical trials.

Using approved materials may help Smith's team overcome nanotechnology's perception problem, Dr. Chan said.

"In this case, a company who translates these technologies would really have to focus on proving they are nontoxic. (But) selecting a design with components that are already approved for clinical use may make the translation process faster. The focus will be on therapeutic efficiency," Dr. Chan said.

SOURCE: http://bit.ly/1GzTsdt Paper number NEMB2015-8112, Track 5, American Society of Mechanical Engineering Global Conference on Nanoengineering for Medicine and Biology, 2015.