Smart Nanoparticles Light Up Brain Cancer and Target What Surgery Misses

Glioblastoma is the most aggressive form of brain cancer. Its cells spread into nearby healthy tissue, so surgeons cannot remove it all without harming the brain, and the blood-brain barrier — a layer blocking most drugs and radiotherapy from reaching brain tissue — limits treatment. These obstacles help explain a five-year survival rate of only about 7 percent.

Researchers at the University of Technology Sydney (UTS), Harvard University and Henan University have built a 'double-punch' platform from nanoparticles — particles measured in billionths of a metre — aimed at both problems, published in Science Translational Medicine. Its core is a thin, two-dimensional sheet studded with platinum atoms placed one at a time, using a method adapted from semiconductor manufacturing.

The sheet switches between two roles under the same near-infrared light: it images tumors during surgery, then delivers phototherapy — a light-based treatment that destroys cancer cells. A fluorescent dye on the sheet glows under the same invisible wavelength, letting surgeons see tumor clusters as small as 44 micrometers, beyond current clinical imaging tools, said Dr. Bingyang Shi of UTS. A targeting molecule helps it cross the blood-brain barrier and accumulate in glioma, or brain tumor, cells.

After the visible tumor is removed, the same material is placed in the surgical cavity and reactivated with the same light. Platinum atoms convert the tumor's hydrogen peroxide into oxygen, countering the low-oxygen conditions that shield cancer cells from treatment, while the light generates heat and reactive molecules that destroy microscopic cancer cells surgery could not reach, cells that can otherwise fuel recurrence.

In mice with glioblastoma, this approach reduced recurrence after surgery: every treated mouse was alive at 60 days, versus 42 days for mice given surgery alone, with no neurological or motor impairments detected afterward. The researchers say the technology has so far been tested only in mice, not people, and its performance needs confirming at the scale of a human brain.