Researchers at MIT University in the US have created the first capsule-sensor, containing genetically modified bacteria, which can diagnose bleeding in the stomach.
It is actually a bacteria “chip” that combines sensors from living microorganisms with electronics of very low energy consumption. The bacterial-electronic sensor transforms the “signal” (i.e. the biological response) of the bacteria into a wireless electronic signal, which can then be read by a “smart” cell phone. With the help of a special Android app, these data can then be analyzed.
Researchers, who made the publication in “Science” magazine, said:
“By combining modified biological sensors with low-energy wireless electronics, we can detect biological signals in the body and in near real-time, thus opening up new diagnostic capabilities.”
In recent years, synthetic biologists have made great progress in modifying bacteria so that they respond to specific environmental stimuli, e.g. pollution, or biomarkers of a disease.
MIT researchers have modified a strain of the known E.coli bacteria to emit light when it comes into contact with the “hemi” substance in the gastrointestinal tract, which is a component of the blood.
The bacteria are introduced along with the electronics (phototransistors, microprocessors) into a capsule about 3.5 centimeters long that only needs 12 microwatts of electricity to get from a 2.7 volt micro-battery, enough for about a month and a half use.
Experiments have so far been successful in pigs, detecting any traces of blood in their stomach, and going on in humans. The capsule can be used in the future either for single use or staying in the stomach for days and weeks, constantly sending signals.
Today, if a patient suspects a bleeding due to a gastric ulcer, he should undergo gastroscopy with an endoscope. The new capsule may in the future make it unnecessary.
Researchers will further shrink the sensor while examining whether it can be used for other gastrointestinal conditions beyond bleeding. They will also try to incorporate other types of bacteria other than E.coli into the sensor.