The nanoparticles used in this study were prepared from a novel biodegradable polymer poly(glycerol adipate). The polymer has been further modified to enhance incorporation of drugs and make the nanoparticles more effective.
To test the nanoparticles, the investigators developed a new in vitro system that should prove useful in a variety of brain cancer studies. "The interaction of tumor cells with brain cells varies between different tumors and different locations within the brain," explained Terence Parker, Ph.D., another investigator involved in this study. "Using three-dimensional culture models is therefore important in ensuring that the behavior of cells in culture is similar to that seen in real life."
Tumor cell aggregates have been used as cell culture models of cancer cells for many years. Similarly, thin brain slices from newborn rats can be cultured for weeks and are an important tool in brain biology. In the cell co-culture model now reported, these two techniques have been brought together for the first time. Brain tumor cell aggregates were labeled with fluorescent iron microparticles and grown on normal newborn rat brain tissue slices.
The double-cell labeling technique allowed investigation of tumor cell invasion into brain tissue by either fluorescence or electron microscopy from the same samples. Using these techniques, the tumor aggregates were found to invade the brain slices in a similar manner to tumors in the body.