Implanting an oxygen-consuming battery in mice with cancer caused their tumors to shrink or disappear within two weeks when used with an experimental class of cancer drugs.
As most tumors grow, they consume oxygen from the non-cancerous tissues around them, so the tumor cells become oxygen-starved or hypoxic. A class of drugs, called hypoxia-activated prodrugs (HAPs), seeks to exploit this trait by killing only cells that exhibit hypoxia, so that healthy cells are less affected, reducing treatment side effects. . But no HAPs are approved for clinical use due to limited evidence of their effectiveness.
NOW, fan zhang at Fudan University in Shanghai, China, and his colleagues have developed an autoloader, implanted battery flowing salt water injected around it causing the battery to produce a very low voltage electricity and consume oxygen. By creating a hypoxic environment, the battery should optimize the action of PAHs.
“The battery can cover the tumor and persistently consume the oxygen in it for more than 14 days, which is much longer than previous agents. [that worked for] usually no more than two days,” says Zhang.
Zhang and his team implanted the battery in some of the armpits of 25 mice with breast cancer. Five received the working battery and the HAP treatment. The remaining mice were organized into groups where they received no treatment, only HAP drugs, an implanted battery that did not work, or only the working battery, which can work for up to 500 hours in mouse tissue.
Fourteen days later, the tumors had shrunk by an average of 90% in the five mice that had received the working battery and the HAP treatment, and they had completely disappeared in four of these mice. The tumors remained the same size or grew in the other groups of mice.
Although the battery poses no safety concerns when used in mice, the safety bar is higher for humans, so further research is needed to ensure it is tissue compatible. humans before being tested in humans, says Zhang.
Randall Johnson at the University of Cambridge says that inducing hypoxia in tumors can have downsides, such as an increased tendency for cancer to spread elsewhere in the body. Although this did not occur in mice, the costs and benefits of battery use in humans should be assessed before any human treatment, he says.