Neuro-oncology: Nanoparticle imaging could guide brain tumour surgery

摘要

A team of US researchers has developed a gold-silica nanoparticle that could be used for molecular imaging to guide surgery for brain tumours. The particles showed promise in mouse models of glioblastoma, the most aggressive form of brain cancer. "We chose to focus on the brain because it is very important to spare normal brain tissue in glioblastoma surgery" explains Sam Gambhir, who led the study.To generate a model of glioblastoma, the researchers implanted human glioblastoma cells into the striata of mice. Nanoparticles were then administered by injection into the tail vein. Gambhir and colleagues hypothesized that the nanoparticles would only enter the brain at regions of tumour-driven damage to the blood-brain barrier, enabling targeting to the tumour site.The 120-nm particles were coated with gadolinium (Gd) to enable imaging with MRI. In addition, the core, being made of gold, is well-suited to a new technique called photoacoustic imaging, whereby light energy is used to heat the imaging agent, which then emits ultrasound waves. Moreover, between the gold core and the Gd coating was a Raman-active layer, which emits low levels of light at signature frequences, allowing high-resolution visualization of the particles using Raman imaging.