Chemotherapy is a type of cancer treatment that uses powerful chemicals to destroy cancer cells. It is usually delivered directly into the patient’s veins using a catheter. To prevent bacterial infection, the catheter, and the equipment it is attached to, is usually coated with silver.
Now, a study led by the Norwegian University of Science and Technology (NTNU) in Trondheim, shows that the antibacterial silver coating used on catheters degrades some chemotherapy drugs and that this could potentially reduce their effectiveness.
The researchers report their findings in the journal 2D Materials.
Senior author Justin Wells, an associate professor of physics at NTNU, says:
“We wanted to find potential problem sources in the tubes used in intravenous catheters. An interaction between the coating and the drugs was one possibility. Chemotherapy drugs are active substances, so it isn’t hard to imagine that the medicine could react with the silver.”
For their investigation, Prof. Wells and colleagues focused on 5-Fluorouracil (5FU), one of the most commonly used chemotherapy drugs. For instance, 5FU is used to treat cancers of the head and neck, bowel, breast, stomach, ovaries and esopaghus.
The researchers used X-ray photoemission spectroscopy (XPS) to look at how the drug reacts with the type of silver used to coat catheters and other medical devices.
Prof. Wells explains that as far as they know, reactions between chemotherapy drugs and the substances they come into contact with have never been studied like this before. The assumption is they always enter the body fully intact.
The XPS machine he and his colleagues used is located at the synchrotron lab MAX IV at Lund University in Sweden.
There, they demonstrated that the antibacterial silver coating catalytically decomposes 5FU.
In their paper, the researchers note that not only does the reaction impair the effectiveness of the chemotherapy drug, but it also releases hydrogen fluoride, a gas that could potentially harm the patient and damage the medical equipment.
The team then switched their attention to graphene – a nanomaterial made of extremely thin flakes of carbon that are only one atom thick. Again, they used the XPS machine to look at how the material reacted with 5FU.
They decided to investigate graphene because they expected it to be chemically inert. They also note that while it has been suggested as a coating for medical equipment, its potential use as a coating material in chemotherapy drug delivery systems “appears to have been entirely overlooked.” Prof. Wells explains:
“Graphene is a nonreactive substance, and is sometimes referred to as a magical material that can solve any problem. So we thought that it might be a good combination with the chemotherapy drugs.”
Their hunch proved to be correct – 5FU did not react with the graphene.
The team believes it should be possible to coat catheters and similar medical devices with very thin layers of graphene.
Prof. Wells concludes that they hope their work will help make cancer treatment more effective.
The team would now like to study the reactions of chemotherapy drugs to other substances and coatings used on medical devices.
In February 2015, Medical News Today learned that graphene may itself have anticancer potential. Writing in the journal Oncotarget, a team from the University of Manchester in the UK describes how graphene oxide can selectively target cancer stem cells and disrupt signals on their membranes.