Most of us would swallow a pill before being poked by a needle, yet sufferers of chronic illnesses are regularly required to administer their medicine intravenously. A team of researchers from MIT and Brigham and Women's Hospital (BWH) has developed a new type of nanoparticle that could afford patients the choice – potentially making uncomfortable injections a thing of the past in the treatment of a range of chronic diseases.
Nanoparticles carrying drugs or short interfering RNA have shown great potential for the treatment of a variety of diseases, including cancer. If taken orally, however, they need to cross the intestinal lining into the bloodstream. This lining consists of a layer of epithelial cells that come together to form a barrier that is impenetrable to the nanoparticles, thereby necessitating the use of injections to be an effective form of treatment.
In developing the new nanoparticle, the researchers led by Omid Farokhzad MD built on previous research revealing how babies absorb antibodies from their mother's milk. When ingested, these antibodies attach themselves to a cell surface receptor called FcRN, which allows them to slip through into the bloodstream through the otherwise impenetrable cellular barrier.
As FcRN receptors are also found in adult intestinal cells, coating the nanoparticles with Fc proteins (the part of the antibody that attaches to the FcRN receptor) and administering them orally in mice, caused the particles to grab hold of the FcRN in the intestinal lining and gained them and their payload entry into the bloodstream.
"It illustrates a very general concept where we can use these receptors to traffic nanoparticles that could contain pretty much anything," said Rohit Karnik, MIT Associate Professor and one of the study's authors. "Any molecule that has difficulty crossing the barrier could be loaded in the nanoparticle and trafficked across."
Using the same principle, the researchers are hopeful of designing nanoparticles with the ability to cross other barriers, which could be used to treat other conditions, such as diabetes, arthritis and high cholesterol.
"If you can penetrate the mucosa in the intestine, maybe next you can penetrate the mucosa in the lungs, maybe the blood-brain barrier, maybe the placental barrier," says Farokhzad.
The team's research is published in the online edition of Science Translational Medicine.
Update (Dec. 6, 2013): This story originally stated that diabetes sufferers injected insulin intravenously. Thanks to the commenters who pointed out this error, which has now been corrected. Ed.
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