Bioinspired delivery device increases lifetime of drugs

A drug delivery device inspired by the teeth of a hookworm can significantly increase the half-life of drugs, researchers have found.

The researchers, led by a team from John Hopkins University in Baltimore, developed a gastrointestinal (GI) tract drug delivery device that grabs on to the colonic mucosa and is retained there for up to 24 hours.

Sharp microtips on the device mimic the teeth of hookworms, allowing the device to be retained on the intestinal mucosa. The increased retention time extends the half-life of drugs better than the current therapeutics.

The paper, first published in Science Advances, has demonstrated the shape-changing, self-latching, parasite-inspired theragrippers were retained in the GI tracts of live animals for 24 hours by grabbing on to the mucosal tissue.

"These results provide first-in-class evidence that shape-changing and self-latching microdevices enhance the efficacy of extended drug delivery," according to the paper. "The administration of drugs through the GI tract (rectal route) offers improved compliance over injectables and consequently better treatment outcomes.

"Drugs administered via the GI tract are efficiently absorbed into the systemic circulation, in part due to the enormous intestinal surface area and rich vascularization of the GI tract mucosa. While the oral route is the more preferred form of drug administration across all age groups, the rectal route is advantageous in the pediatric population as well as during medical emergencies, such as with unconscious patients."

Although the researchers are excited about the prospect of such improved drug delivery, more work needs to be carried out to make sure it is effective and safe. Evaluations should include whether it adversely affects intestinal permeability, commonly known as leaky gut. 

This phenomenon, increasingly common, is where bacteria and toxins from the gut leak into the bloodstream.

The researchers wrote that "in designing these devices we overcame several engineering challenges." One was how to trigger the latching of the microtips. They solved the problem by using a thermal trigger. The with the microtips are open initially, but then close when body temperature is reached. 

Ketorolac, a widely used pain reliever, was used as the demo drug in the animal model.