Together, these peptides and nanoparticles proved extremely effective at treating two different mouse models of glioblastoma. In the first model, treated mice survived significantly longer than untreated mice. In the second model, untreated mice survived for only eight to nine weeks. In sharp contrast, treatment with this nanosystem cured all but one of ten mice. What's more, in addition to providing therapy, the nanoparticles could aid in diagnosing glioblastoma; they are made of iron oxide, which makes themand therefore the tumors they targetvisible by MRI, the same technique already used to diagnose many health conditions.
In a final twist, the researchers made the whole nanosystem even more effective by administering it to the mice in conjunction with a third peptide. Dr. Ruoslahti and his team previously showed that this peptide, known as iRGD, helps co-administered drugs penetrate deeply into tumor tissue. iRGD has been shown to substantially increase treatment efficacy of various drugs against human breast, prostate, and pancreatic cancers in mice, achieving the same therapeutic effect as a normal dose with one-third as much of the drug. Here, iRGD enhanced nanoparticle penetration and therapeutic efficacy.
"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
|Contact: Heather Buschman|
Sanford-Burnham Medical Research Institute