Early Detection of Cancer

The earlier a physician detects a tumor, the better the patient’s chances of survival are. Prospectively, a new testing system is supposed to help identify the incipient disease. The technology is based on a microchip: on it are tiny canals in which a patient’s blood sample circulates. The chip detects marker proteins characteristic for cancer. The markers’ concentration measured in the patient’s blood is supposed to help the physicians diagnose the disease at an early stage. Though there are similar systems existent, they do not measure as exact and require a greater number of molecules in the blood to attest the tumor markers. Moreover, the tests need to be ran in the laboratory, which is time consuming and costly. A compound project promoted by the German Ministry of Education and Research and coordinated at the Fraunhofer Institute for Applied Information Technology is expected to take remedial action here. The new sensor’s centerpiece – biofunctionalized nanoparticles - is developed by researchers at the Fraunhofer Institute for Silicate Research.
“We have improved the limit of detection by the factor one hundred” says Dr. Jörn Probst, head of the Life Science Business Unit at the ISC. “If there used to be one hundred molecules existing in a certain amount of blood to prove tumor markers, now, we only need one. Therefore, diseases might be detected a lot earlier than by using conventional methods.”

But how does the biosensor integrated into the chip identify the few biomolecules in the blood that are characteristic of a certain disease? “We have attached nanoparticles studded with antibodies on top of the sensor electrode that pick out the sought proteins specifically. In order to do so, we keep pumping the blood past the electrode’s surface. Similar to a river, the current is strongest in the middle of the canal, but slower on the banks. Hence, we have constructed a sort of fishing rod from nanoparticles, recording antibodies in the blood stream’s middle, where the largest number of proteins pass by per time unit.” If an antibody has detected an appropriate protein (the tumor marker), the electrical charge distribution shifts. This can be measured by the electrode.

The researchers are currently working on a demonstrator combining four biosensors reacting to specific molecules. Moreover, they are trying to demonstrate several tumor markers at the same time. In a few years, the system will be put on the market.

Source: Fraunhofer-Gesellschaft