With just one third of the standard dose of cisplatin, researchers successfully shrank tumors in mice, without sacrificing efficacy. They were able to do this by encapsulating the prodrug form of the agent in a nanoparticle, which they then targeted to prostate tumor cells.
Because less drug is used, the hope is that potentially severe side effects will be reduced, for cisplatin, the kidney and nerve damage.
In addition, the nanoparticle delivery system, which included a coating of molecules that bind to prostate-specific membrane antigen, increased the amount of cisplatin that reached the tumor. By encasing a derivative of cisplatin in a hydrophobic nanoparticle, researchers found that the drug circulated in the bloodstream for 24 hours, which is five times longer than conventional cisplatin. They also noted less accumulation in the kidneys.
The researchers, from Massachusetts Institute of Technology and Brigham and Women’s Hospital, published their findings online January 11, 2011 in the Proceeding of the National Academies of the Sciences USA. This research updates their previous efforts, which showed that the technology worked in vitro. The team now plans to move to human trials.