Microbots successfully orally administered in pill form.
About the width of a human hair, micromotors are self-propelled microscopic robots designed to perform a host of biomedical tasks, such as drug delivery and ablation. However, keeping these devices intact as they travel through the body remains a hurdle. Now, a study from researchers at UCSD develops a way to encapsulate microbots into pills. The team state that their pill’s coating successfully protects the devices as they traverse the digestive system prior to releasing their drug payload. The study is published in the journal ACS Nano.
Recent studies from the lab utilised microbots coated with an antibiotic to treat ulcers in mice, which produced better results than using the drugs alone. However, it was shown that body fluids, such as gastric acid and intestinal fluids, can compromise the effectiveness of micromotors and trigger early release of their payloads, with some of the micromotors getting trapped in the esophagus. The current study develops a way to protect and carry these devices into the stomach without compromising their mobility or effectiveness.
The current study develops a pill composed of a pair of sugars, namely lactose and maltose, which can encapsulate tens of thousands of micromotors made of a magnesium/titanium dioxide core loaded with a fluorescent dye cargo. These sugars were chosen because they are easy to mold into tablet, can disintegrate when needed and are nontoxic. Results show these pills improve the release and retention of the micromotors in the stomach compared to those encapsulated in silica-based tablets or in a liquid solution when given to mice. Data findings show that encapsulating micromotors in traditional pill form improves their ability to deliver medicines to specific targets without diminishing their mobility or performance.
Results show that the microbots successfully impel in gastric fluid, providing higher cargo retention onto the stomach lining compared to orally administrated free micromotors or passive microparticles. Data findings show that the micromotor pills and loaded micromotors also retain the same characteristics after extended storage in harsh conditions.
The team surmise they have combined the advantages of traditional pills with the efficient movement of micromotors to offer an innovative route for administrating microbots orally for biomedical applications. For the future, the researchers state that their work opens the door to the use of synthetic motors for in vivo treatment of diseases.