Implantable Oxygen-Eating Battery to Combat Cancer

The mainstream cancer treatment, including chemotherapy and radiotherapy, often causes various side effects and intense physical suffering to the patients. Recently, a research team from Fudan University has come up with a better approach to combating cancer. 

An implantable self-charging battery that consumes oxygen in cancer cells which helps to kill them consequently is reported in the journal Science Advances.

Related article: Latest Discovery in Metabolic Pathways of T-Cells Opens New Door to Immunology Research 

An Approach to Boost Hypoxia-Activated Prodrugs Efficacy

Solid tumors, such as those that can develop in breast cancer, have a common characteristic of rapid growth, which exceeds the limitation of blood vessel reconstruction. This means that the center of many tumors can be hypoxic, with much lower oxygen levels than the surrounding tissue.  

The hypoxic microenvironment helps cancer cells to escape the host immune system as the body’s immune cells often cannot survive long enough to kill the cancerous cells. Moreover, hypoxic cells are also resistant to standard treatments like radiotherapy and chemotherapies, as there is not enough blood flow to deliver a deadly dose.

Scientists started to develop hypoxia-activated prodrugs, which are hooked to a linking chemical that ensures the drug becomes active only in a low-oxygen environment, making it less harmful to ordinary body tissues.

However, hypoxia-activated prodrugs failed in clinical trials, as solid tumors may not be evenly hypoxic or simply not hypoxic enough. The scientists aimed to create a way to make tumors more hypoxic, to give the prodrugs a better chance.  

The Battery-TPZ Implantation Show Promising Efficacy on Cancer Cells

So the researchers and their colleagues deployed a tiny, flexible battery that could partially wrap around a tumor. The battery system includes a self-charging saltwater battery and an anticancer drug called tirapazamine (TPZ). The saltwater battery identifies low-oxygen tumor microenvironments and then maintains the hypoxia in those locations until TPZ destroys the cancer cells. Since the battery regulates the tumor conditions and TPZ only targets cells in low-oxygen conditions, healthy body cells can remain unscathed.  

Researchers tested the battery system on five mice. Within two weeks, it reduced cancer tumor volumes by 90% in four of them.

The findings are impressive, however, the system deployed only in mice, and specifically targeted breast cancer. It means that the harm of battery implantation in the human body and the efficacy of other cancer cell types remains unknown. Thus, it is necessary to conduct large-scale in vivo studies and to develop better drug combinations to eradicate cancer cells.

Author

Nai Ye Yeat