Scientists are working to get blood-brain barrier permeating drugs to target specific cells and treat tumors
Orange County, CA - May 26th 2017 - Scientists worldwide have been in the development of therapeutic drugs able to enter the blood- brain barrier and treat tumors. However, the larger obstacle to combat came in programming the drugs to be selective and only affect specified cell types. William Weir, writer for the Yale News, poses the question and basis for this study: “By making nanoparticles bioadhesive, or “sticky,” the researchers have answered a long-standing question: Once you get the particles to the brain, how do you get them to interact with the cancer cells there?” Scientists at Yale University have been working with nanoparticles to help direct drugs into the brain. These specific polylactic acid nanoparticles have the capacity to permeate the blood-brain barrier and enter the spaces most effective in treatment. To make the nanoparticles more prone to cellular uptake in the brain, scientists attached them to chemical bio-adhesive end-groups called aldehydes. It was this process that gave birth to the nickname “sticky.”Aldehyde is an organic compound that is attracted to amine, a compound found within many proteins, used to attract the nanoparticles to targeted cells. The Yale scientists noted high rates of success with the tumors accepting the modified nanoparticles.
Though drugs have previously been administered into the brain, such ventures have failed to attach to useful cells. Scientists believe this was due to past trials’ coating the nanoparticles in a polymer coating to equip them with “stealth” properties, allowing the particles to travel to the brain unnoticed by the body’s immune system. However, the consequences of these stealth properties are that cells are unable to distinguish the correct targeted particles. “They’re just kind of in the space between the cells, and not really doing what they’re supposed to be doing,” said co-lead author Eric Song, a graduate student at the Yale School of Medicine. Scientists then decided to move to rat trials composed of two groups, - one with brain tumors and one with healthy brains.Not only did the targeted nanoparticles aid in treatment, but the side effects, such as toxicity, to the non- targeted cells were minimized.
This work is particularly ground breaking as no previous work has been done on “sticky” nanoparticles. “Until now, research has focused on whether you can load the nanoparticles with drugs and whether we can get them into the brain at all, without thinking too much about what cells they go to,” said senior author W. Mark Saltzman, the Goizueta Foundation Professor of Chemical and Biomedical Engineering, professor of cellular and molecular physiology, and member of the Yale Cancer Center. “This is the first exploration of the particles’ affinity for different cells.”