Nanobubbles Deliver Targeted Cancer Drugs Using Ultrasound

A new targeted drug delivery method uses ultrasound to image tumors, while also releasing the drug from nanobubbles into the tumor.

Cancer drugs can be targeted to tumors by delivering them in packets of nanoparticles, then releasing them with ultrasound. But this approach can be difficult because it requires a way to image the tumor prior to treatment.

Natalya Rapoport, Ph.D., D.Sc., of the University of Utah in Salt Lake City and colleagues describe a new method of drug delivery that may address this problem. Nanobubbles filled with the chemotherapy drug doxorubicin were injected into mice. The bubbles accumulated in the tumors, where they combined to form larger microbubbles. When exposed to ultrasound, the bubbles generated echoes, which made it possible to image the tumor. The sound energy from the ultrasound popped the bubbles, releasing the drug. In mice treated with this method, the nanobubbles were more effective at blocking tumor growth than other nanoparticle delivery methods.

Microbubble formulations have been developed for combining ultrasonic tumor imaging and ultrasound-enhanced chemotherapeutic treatment, the authors write.

Contact: Natalya Rapoport, natasha.rapoport@m.cc.utah.edu, (801) 581-8990

Gene May Promote Resistance to Chemotherapy Drugs

A gene known as HDAC1 may be a good target for drugs to treat multidrug-resistant neuroblastoma, a cancer that develops in immature nerve cells and is prevalent in children.

Drug resistance could explain why about 50% of high-risk neuroblastoma patients die of the disease. Nino Keshelava, M.D., of Childrens Hospital Los Angeles and colleagues studied several human neuroblastoma cell lines to identify genes that cause drug resistance.

They found that HDAC1 was overexpressed in m
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Contact: Liz Savage
jncimedia@oxfordjournals.org
301-841-1287
Journal of the National Cancer Institute
10-Jul-2007