Treating diseases in the brain has always been challenging for scientists because crossing the body’s natural barriers to the organ has proven itself time and again to be nearly impossible. Now, scientists at the University of Michigan say nanoparticles are crucial to breaking through the almost impenetrable blood-brain barrier.
This accomplishment is permitting cancer researchers to administer a game-changing medication to obliterate brain tumors such as Glioblastoma, which is the most widely recognized and deadliest type of brain cancer in adults. Less than five percent of patients live longer than five years after their diagnosis. The average survival length for patients with Glioblastoma is about 18 months.
This breakthrough carries medication through the nanoparticles intravenously. They sneak past the blood-brain barrier to target malignant tumors forming and deliver the cancer-cell killing drug straight to the source.
The scientists say that seven of the eight mice given this treatment, coupled with a combination of radiation, survived their cancers. What’s more is when there was a recurrence of the Glioblastoma in those seven mice, their immune systems stopped the cancer from forming altogether without needing any more treatments!
Co-senior author Joerg Lahann in a university release exclaimed, “It’s still a bit of a miracle to us. Where we would expect to see some levels of tumor growth, they just didn’t form when we rechallenged the mice. I’ve worked in this field for more than 10 years and have not seen anything like this!”
R.C. Schneider Collegiate Professor of Neurosurgery and co-author Maria Castro adds, “This is a huge step toward clinical implementation. This is the first study to demonstrate the ability to deliver therapeutic drugs systemically, or intravenously, that can also cross the blood-brain barrier to reach tumors.”
The researchers say infusing nanoparticles with cancer drugs delivered a fatal blow to the primary brain tumor and helped the patient’s immune system recognize and attack cancer cells. Castro adds she’s known for five years how she wanted to attack brain cancer but needed a way to do it. She says her approach stops a specific signal cancer cell’s broadcast. This signal, STAT3, tricks immune cells into letting cancer inside the patient’s brain. Castro’s treatment inhibits STAT3, allowing the immune system to eliminate cancer cells, which are now exposed to the body’s defenses. The only catch was developing a method to safely get this inhibitor beyond the blood-brain barrier.
Both teams worked within the university’s Biointerfaces Institute on a nanoparticle delivery system. The authors say a protein called human serum albumin is one of the few molecules in blood that successfully crosses the barrier. The protein was the building block for the new nanoparticles, which use manufactured atoms to connect the human serum albumins. The team, at that point, joined the STAT3 inhibitor and a peptide called iRGD. This compound operates as a tumor homing device for the cancer-killing nanoparticles.
In the first study, mice received several doses of the nano-prescription over three weeks. They found their survival length jump from 28 days to 41 days in the mice that responded to the treatment. In the second study, they added radiation therapy to the mix. That’s when the seven of the eight mice made it through and were determined tumor-free.
Researchers are hoping their synthetic protein nanoparticles will soon provide doctors with a new option for destroying currently “undruggable” tumors.