The 72-Hour “Golden Window” After Brain Tumor Surgery: Nanoparticles Breach the Blood-Brain Barrier

A new study found that administering an existing cancer drug in nanoparticles immediately after brain tumor surgery could deliver the drug across the blood-brain barrier and prevent recurrence.

According to the biotechnology news outlet Fierce Biotech on the 29th (local time), researchers at the University of Manchester published these findings from a preclinical glioblastoma study in the international journal Science Translational Medicine.

The researchers loaded the existing cancer drug doxorubicin into liposomal nanoparticles and administered it to mice that had undergone brain tumor resection. They found that when administered between 15 minutes and up to 72 hours after surgery, the drug crossed the blood-brain barrier (BBB) and accumulated at the tumor margins.

Glioblastoma is the most lethal primary brain tumor occurring in adults. It is highly aggressive, with a postoperative recurrence rate approaching 100%, and drug treatment is extremely difficult because of the blood-brain barrier that protects the brain.

To address this challenge, the researchers used two strategies. The first was to take advantage of the temporary disruption of the blood-brain barrier caused by surgery, and the second was to conceal the drug inside nanoparticles—a “Trojan horse”—to carry it across the barrier.

Kostas Kostarelos, a professor of nanomedicine at the University of Manchester, explained that the team “deliberately chose a ‘low-tech’ approach using existing liposomes whose patents had expired.” He added, “We wanted to prove the hypothesis that highly sophisticated nanoparticles are not necessary for this concept to work.”

The researchers implanted glioblastoma cells into the brains of mice and surgically removed the tumors after they grew. They then administered doxorubicin-loaded liposomes intravenously at different time points after surgery: 15 minutes, 3 hours, 24 hours, 48 hours, 72 hours and 7 days.

As a result, the drug accumulated around the tumor only when administered within 72 hours after surgery. No drug was detected after 7 days, suggesting that the “golden window” immediately after surgery is important.

The researchers assessed the finding as a potential way to overcome the strength of the blood-brain barrier. Dr. Thomas Keesby, co-corresponding author, said, “We will explore whether other types of treatments, such as cell therapies and antibody therapies, can also take advantage of this time window.”

Professor Kostarelos said the team was also considering collaboration with biotechnology companies to advance the research toward human clinical trials. “What is distinctive about this finding is that the nanoparticles themselves do not need any special functionality,” he emphasized. “Because it can be applied broadly across multiple technologies and treatment approaches, it is highly versatile from a clinical application perspective.”