Nanoparticles loaded with chemotherapy drugs or short interfering RNA, which can turn off selected genes, are currently in clinical trials to treat cancer and other diseases.
After the particles are intravenously injected into patients, they seep through the leaky blood vessels that typically surround tumors and diseased tissue, and release their payload at the tumor site.
But new research, published in Science Translational Medicine, is exploring alternatives to shots.
The researchers claim to have made breakthroughs that will smooth the way for the oral delivery of these "micro medicines." They explain that oral administration has proved challenging in the past because it cannot travel across the intestinal epithelium into the bloodstream.
Senior author and director of the Laboratory of Nanomedicine and Biomaterials at Brigham and Women's Hospital (BWH), Omid Farokhzad explains:
"The key challenge is how to make a nanoparticle get through this barrier of cells. Whenever cells want to form a barrier, they make these attachments from cell to cell, analogous to a brick wall where the bricks are the cells and the mortar is the attachments, and nothing can penetrate that wall."
The researchers revisited previous research that showed how babies absorb antibodies from their mother's milk, boosting their own immune systems. In this case, the antibodies hook onto a cell surface receptor, known as FcRN, and this grants them access through the cell wall.
This type of drug delivery could be especially useful in developing new treatments for conditions such as high cholesterol or arthritis. While patients may be reluctant to make frequent visits to a doctor's office to receive a shot, they would be more likely to take nanoparticle pills regularly, say the researchers.
The researchers are now optimizing how the nanoparticles deliver drugs prior to testing on animals.
NTJ/BA