Getting drugs into the brain is a bit of a holy grail, but researchers at Johns Hopkins University believe that they are a step closer with nanoparticles that can penetrate into the brain, potentially preventing recurrence of cancer after surgery by destroying any remaining tumor cells.
The historical issues with drug delivering nanoparticles are that they stick to the cells at the point of dosing and don't spread farther into the tissue. To be effective at preventing recurrence, the drug needs to penetrate deeper into the brain.
In an attempt to make nanoparticles "slippery," researchers created plastic nanobeads about a thousandth of the diameter of a human hair and coated them with PEG (polyethylene glycol). After labeling them with fluorescent tags, they injected them into slices of rodent and human brain tissue, and into live rodent brains, and found that the PEG-coated beads spread farther into the brain tissue than the uncoated beads. The next step was to try PEG-coated particles of the cancer chemotherapy drug paclitaxel in rat brains, and these were distributed through the tissue. The particles could also carry 5 times more drug and release it three times more slowly.
This is still at a very early stage, and the team's next step is to see if the drug-loaded and PEG-coated nanoparticles can slow tumor growth or recurrence in rodents. The system may also have potential in other brain diseases, such as multiple sclerosis, stroke, traumatic brain injury, Alzheimer's disease and Parkinson's disease.