The project is being led by MIT's Robert Langer, who's worked on similar projects in the past. Back in July 2015, his team produced a similarly-focused material, designed to allow for single-use, ultra long-term drug delivery.
The new research is a step closer to clinical use, providing a solution that – conceptually at least – would allow for practical long-term medication delivery. Designed to reside in the gastrointestinal tract, the device makes use of a material called a mucoadhesive.
As the name suggests, the material is capable of sticking to the mucosal lining of organs. Its use has been trialled before, but has been found to be problematic, as food and liquids can easily become stuck to it, shifting it out of place before drugs can be delivered.
The researchers used a mucoadhesive polymer called Carbopol for one side of the pill, but for the other – the section tasked with repelling food and liquid – they used a cellulose acetate. That side was textured to mimic a lotus leaf, which has tiny protrusions that make it extremely hydrophobic. Once the texturing was complete, the surface was flourinated and lubricated to make it repel practically anything it comes into contact with.
The dual-sided pill was then loaded with drugs and tested using intestinal tissue from pigs, alongside fully mucoadhesive and fully omniphobic pills. To simulate the environment in which the pills are designed to function, the researchers flowed a mix of liquids and small piece of rice and bread along the tissue.
In testing, the omniphobic variant moved along the tissue in just a single second, while the mucoadhesive pill stayed in place for seven seconds before it was pulled out of place. The two-sided pill performed much better, staying in place for the entire length of the experiment – a full 10 minutes.
With those positive results in the bag, the researchers plan to fine-tune the dual-sided pill, tweaking the amount of time it stays in place, as well as the rate of drug release. They also plan to tune the pill so that it attaches to specific sections of the GI tract.