Nanoparticles weaken and then kill cancer cells with two-drug timed release

MIT's Paula Hammond

Scientists at MIT have engineered a one-two punch for cancer that carries two drugs at a time and has been shown to shrink lung and breast tumors in mice. While other nanoparticles have carried multiple drugs, this one makes use of a specific timing mechanism to get the most out of each treatment.

In a study from 2012, the researchers found that a regimen involving a pretreatment of the cancer-weakening drug erlotinib and then a dose of the cancer-killing doxorubicin was more effective than delivering both at the same time.

Now lead researchers Paula Hammond and Michael Yaffe have published new findings in the journal Science Signaling, demonstrating that the treatment was effective in mice, shrinking triple-negative breast tumors and non-small-cell lung tumors significantly, according to a report from MIT.

MIT's Michael Yaffe

To make this treatment work, the team created liposomes that carry doxorubicin on the inside and erlotinib on the outside. Tagged with folate, they target the tumor cells and start to break down, first releasing the erlotinib and then the doxorubicin. Most importantly, the nanoparticle allows for a lag time of about 24 hours between the peak doses of the drugs, giving them a true one-two punch.

"I think it's a harbinger of what nanomedicine can do for us in the future," Hammond said in a statement. "We're moving from the simplest model of the nanoparticle--just getting the drug in there and targeting it--to having smart nanoparticles that deliver drug combinations in the way that you need to really attack the tumor."

Yaffe added: "It's like rewiring a circuit. … When you give the first drug, the wires' connections get switched around so that the second drug works in a much more effective way."

- here's the MIT report
- get the research abstract