#Expert Research: Biodegradable ultrasound implant could improve brain tumour treatments

One of the challenges in treating certain types of brain cancer is the way that the blood-brain barrier prevents chemotherapy drugs from reaching the tumors they're meant to target.

UConn's Thanh Nguyen, a biomedical and mechanical engineer, is developing new technology that could improve how we are able to treat brain tumors. 

He recently spoke with Physics World about this groundbreaking research:

A new type of biodegradable ultrasound implant based on piezoelectric nanofibres could improve outcomes for patients with brain cancer.

Researchers led by Thanh Nguyen from the the University of Connecticut’s department of mechanical engineering fabricated the devices from crystals of glycine, an amino acid found in the human body. Glycine is not only non-toxic and biodegradable, it is also highly piezoelectric, enabling the creation of a powerful ultrasound transducer that could help treat brain tumours.

Brain tumours are particularly difficult to treat because the chemotherapy drugs that would be effective in tackling them are blocked from entering the brain by the blood–brain barrier (BBB). This barrier is a very tight junction of cells lining the blood vessel walls that prevents particles and large molecules from making their way through and damaging the brain. However, ultrasound can be safely used to temporarily alter the shape of the barrier cells such that chemotherapy drugs circulating in the bloodstream can pass through to the brain tissues.

Currently, to achieve such BBB opening requires the use of multiple ultrasound transducers located outside the body, together with very high intensity ultrasound to enable penetration through the thick human skull bone.

“That strong ultrasound can easily damage brain tissues and is not practical for multiple-time applications which are required to repeatedly deliver chemotherapeutics,” Nguyen tells Physics World.

By contrast, the team’s new device would be implanted during the tumour removal surgery, and “can generate a powerful acoustic wave deep inside the brain tissues under a small supplied voltage to open the BBB”. The ultrasound would be triggered repeatedly as required to deliver the chemotherapy that kills off the residual cancer cells at tumour sites. After a set period of time following treatment the implant biodegrades, thereby eliminating the need for surgery to remove it.

The research, reported in Science Advances, demonstrated that the team’s device used in conjunction with the chemotherapy drug paclitaxel significantly extended the lifetime of mice with glioblastomas (the most aggressive form of brain tumour) compared with mice receiving the drugs but no ultrasound treatment.

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Professor Nguyen focuses on biointegrated materials and devices at nano- and micro-scales for applications in biomedicine, and he's available to speak to media about his research. Simply click on his icon now to arrange an interview today.