Researchers at the Harvard Wyss Institute have developed a nanoparticle aggregate system that releases a drug when it is dispersed using ultrasound. This means that it can be used to deliver toxic chemotherapy drugs directly to a tumor while reducing side-effects in healthy tissues.
Normally, many tumors are treated using chemotherapy drugs that travel throughout the entire body and cause lots of side-effects, such as hair-loss and nausea. Researchers have been working to develop highly specific drug delivery systems that limit the drug to the immediate surroundings of the tumor.
This new technique consists of chemotherapy-loaded nanoparticle aggregates that are injected into the bloodstream. Following, an external ultrasound activation system is energized at the tumor site, causing the aggregates passing through the blood to be disrupted and release their drug payload in the tumor. “We essentially have an external activation method that can localize drug delivery anywhere you want it, which is much more effective than just injecting a bunch of nanoparticles,” says Netanel Korin, co-first author on the study which was recently published in the journal Biomaterials.
The researchers tested their system in a mouse model of breast cancer and the nanoparticle aggregates combined with ultrasound delivered nearly five times the number of nanoparticles to the tumor, compared with aggregates without ultrasound. When the nanoparticles were loaded with a common chemotherapy drug called doxorubicin, the researchers needed only 10% of the normal dose of doxorubicin required to reduce the tumor size by half, showing that highly specific drug delivery can significantly improve drug effectiveness.