|A porous silica nanoparticle is loaded with a pancreaticcancer drug combination that is delivered to and effectively shrinks a human cancer grown in the pancreas of a mouse.
Graphic: Dr. Huan Meng
Scientists at UCLA’s California NanoSystems Institute and Jonsson Comprehensive Cancer Center have combined their nanotechnology expertise to create a new treatment that may solve some of the problems of using chemotherapy to treat pancreatic cancer.
The study describes successful experiments to combine two drugs within a specially designed mesoporous silica nanoparticle that looks like a glass bubble. The drugs work together to shrink human pancreas tumors in mice as successfully as the current standard treatment, but at one-twelfth the dosage. This lower dosage could reduce both the cost of treatment and the side effects that people suffer from the current method.
Pancreatic cancer is difficult to detect early, and symptoms do not usually appear until the disease is advanced. As a result, many people are not diagnosed until their tumors are beyond the effective limits of surgery, leaving chemotherapy as the only viable treatment option. The chemotherapy drug most oft en used for pancreas cancer is gemcitabine, but its impact is oft en limited.
Recent research has found that combining gemcitabine with another drug called paclitaxel can improve the overall treatment effect. In the current method, Abraxane, a nano complex containing paclitaxel, and gemcitabine are given separately. Though this works to a degree, the combined beneficial effect is not fully synchronized because the drugs may stay in the body for different lengths of time.
In mice that received the two drugs inside the nanoparticle, pancreas tumors shrank dramatically compared with those in mice that did not receive the combined drugs in the nanoparticle. Similar comparisons were made with mouse models, in which the human tumors were surgically implanted into the mice’s abdomens in order to more closely emulate the natural point of origin of pancreatic tumors and provide a better parallel to the tumors in humans. In these experiments, the tumors in the mice receiving silica nanoparticles shrank more than the comparative controls. Also, metastasis to nearby organs was eradicated in these mice.
“Instead of just a laboratory proof-of-principle study of any cancer, we specifically attacked pancreatic cancer with a custom-designed nanocarrier,” says Andre Nel, MD, distinguished professor of medicine and associate director for research of the California NanoSystems Institute. “In our platform, the drugs are truly synergistic because we have control over drug mixing, allowing us to incorporate optimal ratios in our particles, making the relevance of our models very high and our results very strong.”
“Use of a Lipid-Coated Mesoporous Silica Nanoparticle Platform for Synergistic Gemcitabine and Paclitaxel Delivery to Human Pancreatic Cancer in Mice,” ACS Nano, March 16, 2015