The right balance for cancer treatment and imaging with nanoparticles

Hongwei Duan from Emory University and Georgia Tech presented self-assembled nanoparticles that he, Shuming Nie, and their colleagues have been developing. These particles are designed to act as a cancer therapy as well as an imaging probe.

Although scientists have developed probes with many functions, it has been a tough to develop a probe large enough to remain in the body long enough to provide therapy yet is small enough to reach the cancer cells. In addition, the probe must leave the body once its task is complete.

Duan has been working on self-assembled nanostructures because they can disassemble to leave the body. The nanostructures he’s been working with are water soluble, allow functional groups to be attached, are around 80 nm in size, and have an IR dye attached for imaging.

The researchers monitored the disassembly of the nanoparticles using single particle imaging and found that as time progressed from 0 to 24 hours, the number of particles decreased. With whole animal imaging of mice, they found that the particles didn’t clear immediately, but did start clearing after a few hours. Tests of the nanoparticles in mice with breast tumors and found that the particles did accumulate in the tumors relatively quickly.

Duan says that the fact that these nanoparticles disassemble helps them get through the interstitial area between the blood stream and the tumor because it speeds their diffusion. He added that being able to image these nanoparticles helps them to optimize the therapy. In one experiment they saw tumors begin to shrink after four injections of the nanoparticles.