Via ScienceDaily: "Glioblastoma is one of the most aggressive forms of brain cancer. Rather than presenting as a well-defined tumor, glioblastoma will often infiltrate the surrounding brain tissue, making it extremely difficult to treat surgically or with chemotherapy or radiation. ... [scientists] developed a method to combine a tumor-homing peptide, a cell-killing peptide, and a nanoparticle that both enhances tumor cell death and allows the researchers to image the tumors. When used to treat mice with glioblastoma, this new nanosystem eradicated most tumors in one model and significantly delayed tumor development in another. ... This is a unique nanosystem for two reasons. First, linking the cell-killing peptide to nanoparticles made it possible for us to deliver it specifically to tumors, virtually eliminating the killer peptide's toxicity to normal tissues. Second, ordinarily researchers and clinicians are happy if they are able to deliver more drugs to a tumor than to normal tissues. We not only accomplished that, but were able to design our nanoparticles to deliver the killer peptide right where it acts - the mitochondria, the cell's energy-generating center. ... In this study, our patients were mice that developed glioblastomas with the same characteristics as observed in humans with the disease. We treated them systemically with the nanoparticles. Once the nanoparticles reached the tumors' blood vessels, they delivered their payload (a drug) directly to the cell's power producer, the mitochondria. By destroying the blood vessels and also some surrounding tumor cells, we were able to cure some mice and extend the lifespan of the rest,"