The flexible microfilm device, which takes advantage of nanodiamonds, an emergent technology, for sustained drug release, resembles a piece of plastic wrap and can be customized easily into different shapes.
The device has the potential to transform conventional treatment strategies and reduce patients' unnecessary exposure to toxic drugs.
The device releases the chemotherapy agent Doxorubicin in a sustained and consistent manner -- a requirement of any implanted device for localized chemotherapy.
"The thin device -- a sort of blanket or patch -- could be used to treat a localized region where residual cancer cells might remain after a tumor is removed," said Dean Ho, assistant professor of biomedical engineering and mechanical engineering at Northwestern's McCormick School of Engineering and Applied Science, who led the research.
For instance, if a surgical oncologist was removing a tumor from the breast or brain, the device could be implanted in the affected area as part of the same surgery. This approach, which confines drug release to a specific location, could mitigate side effects and complications from other chemotherapy treatments.
"Several surgeons at Northwestern's Feinberg School of Medicine, as well as other medical schools and hospitals, are very interested in the device because it is biocompatible and provides such stable and consistent drug release," said Ho.
For the study, the researchers embedded millions of tiny drug-carrying nanodiamonds in the FDA-approved polymer parylene, which is a flexible and versatile material resembling plastic wrap.
A substantial amount of drug can be loaded onto clusters of nanodiamonds, which have a high surface area. The nanodiamonds then are put between extremely thin films of parylene, resulting in a device that is minimally invasive.
For testing the device's drug release performance, the researchers used Doxorubicin, a chemotherapeutic used to treat many types of cancer.
It was found that the drug slowly and consistently released from the embedded nanodiamond clusters for one month, with more Doxorubicin in reserve, indicating a more prolonged release (several months and longer) was possible.
The device also avoided the "burst" or massive initial release of the drug, a common disadvantage with conventional therapy.
The architecture of the device is amenable to housing small molecule, protein, antibody or RNA- or DNA-based therapeutics. This gives the technology the potential to impact a range of treatment strategies where implanted, long-term drug release is needed.
The new work successfully transitions the nanodiamonds from basic materials to serving as a foundation for device manufacturing.
In the area of localized chemotherapy, the team hopes that this technology will bring new levels of treatment efficacy that can complement injected chemotherapy to reduce dosages and decrease devastating side effects.
As a result of the proven biocompatibility and massively parallel deposition capabilities of parylene, the researchers are engaged with pre-clinical trials of the nanodiamond-embedded parylene.
The results of the study are published online by the journal ACS Nano.