Bacteria-on-a-chip
A sensor with glowing bacteria will help detect bleeding in the intestine
Grigory Kopiev, N+1
American researchers have created a swallowable sensor that monitors the presence of blood in the intestine in real time and transmits data to a smartphone. It is based on genetically modified bacteria that luminesce in the presence of the desired substances, as well as a photodetector that registers this radiation and transmits data to the antenna, the developers tell in the journal Science (Mimee et al., An ingestible bacterial-electronic system to monitor gastrointestinal health).
The study of the state of the intestine makes it possible to identify both its diseases, such as intestinal cancer, and diseases of other parts of the gastrointestinal tract at an early stage. For example, in this way it is possible to study the assimilation of food by a person. But usually these studies are carried out using an endoscope, which brings noticeable inconvenience to the patient, and can also affect the data collected and is poorly suited for long-term studies.
Researchers led by Timothy Lu from the Massachusetts Institute of Technology have created a compact swallowable sensor capable of detecting the presence of certain substances in the intestine and transmitting the collected data in real time. Interestingly, the developers used a hybrid system in which the substance sensor consists of both electronics and special bacteria. To do this, they modified the E. coli bacterium, creating a synthetic biological scheme in it. It luminesces in response to the presence of heme, which acts as a marker of bleeding in the intestine. These bacteria are located in a small chamber isolated by a semi-permeable membrane, near which photodetectors are installed.
Device elements (drawings from an article in Science)
After the capsule with the sensor is in an environment with a marker substance, it penetrates into the chamber with bacteria, and the light emitted by them is registered by sensors. After that, the sensor readings are transmitted for analysis to an external device, such as a smartphone or computer.
Prototype of the device
The researchers tested a prototype device on mice, causing them to have intra-intestinal bleeding. The sensor was able to detect an 18-fold increase in the luminosity of bacteria compared to the control group of mice. In addition, the sensor was tested on pigs, having previously injected blood into their digestive tract. Under these conditions, the sensor was also able to detect a multiple increase in the luminosity of bacteria.
Recently, Australian researchers tested a similar sensor of substances in the intestine on humans. It uses a gas and thermal conductivity sensor to measure the concentration of carbon dioxide, hydrogen and oxygen. During the tests, the developers were able to detect differences in the concentration of gases in the food taken by people.
Portal "Eternal youth" http://vechnayamolodost.ru