Tumors of human brain cancer cells were successfully destroyed in the first animal tests with heat.
Rice University bioengineers and physician-scientists at Baylor College of Medicine and Texas Children's Hospital carried out the treatment.
The tests involved nanoshells, light-activated nanoparticles that are designed to destroy glioma tumors with heat and avoid the unwanted side effects of drug and radiation therapies.
The researchers reported that more than half of the animals that received the nanoshell treatment for glioma tumors had no signs of cancer more than three months after treatment.
"This first round of in vivo animal tests suggests that photothermal therapy with nanoshells may one day be a viable option for glioma patients," said study co-author Jennifer West, the Isabel C. Cameron Professor of Bioengineering at Rice and chair of Rice's Department of Bioengineering.
The researchers injected the mice with nanoshells and waited 24 hours for the nanoparticles to accumulate in the tumors. A laser of near-infrared light-which is harmless to healthy tissue -- was shined at the tumor for three minutes. The nanoshells converted the laser light into tumor-killing heat. All seven animals that received the nanoshell treatment responded, but cancer returned in three. The other four remained cancer-free 90 days after treatment.
The results of the new study are available online in the Journal of Neuro-Oncology.