Researchers from the University of Science and Technology of China, Georgia Tech, and Emory University, have developed a new type of nanoparticle that that can deliver chemotherapy directly to tumors in a unique way. These particles are reminiscent of nuclear weapons with multiple warheads because they are pretty large to start with (~100 nm), but release tiny (~5 nm) independent “bomblets” that carry the chemo drug cisplatin into the tumor cells to be killed.
The original nanoparticle is large enough to travel easily through the vasculature and escape wherever a vessel has leaks. Once it finds itself in a high-acidity environment, which exist near tumor sites, the bomblets attached to it break off and enter the cancer cells where a chemical reaction allows the cisplatin to damage nearby DNA, effectively killing the cells.
So far the technology has been tested favorably in laboratory mice, demonstrating that cisplatin gathers in large quantities inside of tumors.
More details according to Emory:
When mice bearing human pancreatic tumors were given the same doses of free cisplatin or cisplatin clothed in pH-sensitive nanoparticles, the level of platinum in tumor tissues was seven times higher with the nanoparticles. This suggests the possibility that nanoparticle delivery of a limited dose of cisplatin could restrain the toxic side effects during cancer treatment.
The researchers also showed that the nanoparticles were effective against a cisplatin-resistant lung cancer model and an invasive metastatic breast cancer model in mice. In the lung cancer model, a dose of free cisplatin yielded just 10 percent growth inhibition, while the same dose clothed in nanoparticles yielded 95 percent growth inhibition, the researchers report.
In the metastatic breast cancer model, treating mice with cisplatin clothed in nanoparticles prolonged animal survival by weeks; 50 percent of the mice were surviving at 54 days with nanoparticles compared with 37 days for the same dose of free cisplatin.