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The treatment of tumors within the GI system has always been a difficult task for medicine. Most times, it will end up requiring invasive surgery.
But technology has evolved greatly and is about to introduce a positive change to that.
Scientists at Caltech have now developed self-propelled microrobots that can deliver drugs to precise spots within the intestines; giving clinicians the ability to monitor and control the activities of these drugs.
Apart from drug delivery, clinicians can use the microrobots to perform microsurgeries in areas of the body that are difficult to reach.
What are Microrobots?
These microrobots are tiny spheres of magnesium that’s coated with various substances which include; gold, perylene, a polymer that doesn’t break down within the GI tract, then finally, the drug that’s to be delivered.
The microrobots are also encapsulated within paraffin wax to resist the acidity of the stomach from affecting them.
The coating, thus, has a tiny hole within it that lets digestive juices in to react with magnesium and generate bubbles that stream out of the hole. As the bubbles come out, they push the microrobot in the opposite direction.
How it Works
In order for this technology to be useful therapeutically, the microrobots are to be ingested orally and allowed to travel to the treatment site.
Once in the target site, a photoacoustic computed tomography system uses infrared light pulses to spot the microrobots. Since infrared light is perfectly absorbed by hemoglobin within red blood cells, the hemoglobin molecules begin to vibrate intensely and this vibration can be spotted using ultrasound sensors. Using the technique, tumor sites and the microrobots that target them can be identified within the intestine.
To activate the microrobots, a continuous-wave near-infrared laser is used to melt the paraffin wax surrounding them, exposing them to the digestive juices that flood into the hole within each microrobot and set off the bubbling reaction. The microrobots get pushed in all sorts of directions since there’s no steering mechanism. Because there’s so many of them and they’re concentrated around the treatment area, many of the microrobots become lodged on the surface of the intestinal wall, releasing the drug within their coating.
“These micromotors can penetrate the mucus of the digestive tract and stay there for a long time. This improves medicine delivery,” said Wei Gao, one of the leaders of the research. “But because they’re made of magnesium, they’re biocompatible and biodegradable.”