Chinese scientists design implantable battery to help kill tumors

Chinese researchers have developed an implantable and self-charging saltwater battery that helps kill tumor cells by regulating the very environment supporting a tumor's growth.

The study was published on Saturday in the journal Science Advances. It describes the battery, which, in combined use with a prodrug called tirapazamine, reduced tumor volume by 90 percent on average over the course of two weeks and eliminated tumors in four out of five mice.

The team from Fudan University, inspired by the electrode redox reaction in batteries, designed an implantable device consisting of biocompatible carbonyl-based polyimide and metallic zinc.

The battery can form a discharge and self-charging cycle to consume oxygen in mouse tumors steadily, thus regulating a tumor's oxygen content and pH level.

It was shown to optimize the tumor-killing effects of tirapazamine to kill tumor cells in mice. The prodrug exploits the oxygen-depleted conditions of tumors to selectively kill their hypoxic cells.

Featuring good plasticity, the salt water battery can be implanted subcutaneously onto the tumor surface to properly cover the tumor, according to the study.

The study demonstrated that the salt water battery could be used as an effective tumor microenvironment regulator for antitumor therapy, said Zhang Fan, a professor at Fudan University and a corresponding author of the paper.

Additionally, no abnormal changes in the body weight, skin and normal organs of the mice were reported during treatment, indicating the battery's in-vivo safety.

"This work is a crossover study between battery technology and biotherapy, which not only provides a new treatment method for antitumor therapy, but also creates a precedent for batteries in biomedical application," said Xia Yongyao, also a professor at Fudan and a corresponding author of the paper.