shape-changing microdevices for extended drug delivery
Thamarasee Jeewandara, Phys.org. and Robert Gorter, MD, PhD.
March 15th, 2021
Shape-changing theragrippers as self-latching drug delivery devices. (A) Scanning electron microscopy (SEM) image of the ventricular teeth of hookworm A. duodenale. The worm uses these sharp teeth to penetrate the mucosa and adheres in the GI tract for up to 2 years. Reprinted from Human Parasitology, 4th Ed. Copyright 2013, with permission from Elsevier. (B) SEM image of a theragripper in the closed configuration. Like the hookworm, the theragrippers are equipped with sharp microtips. Schematic illustrations of (C) a single and (D) many theragrippers attached to the mucosal tissue and releasing encapsulated drug (colored in green). Scale bars, 100 μm (A to D). (E) Conceptual illustration of the rectal administration of drug-loaded theragrippers using a pressure-actuated microfluidic flow controller. Images (C) to (E) were illustrated by L. Gregg. MFCS, microfluidic flow control system. Credit: Science Advances, DOI: 10.1126/sciadv.abb4133
The online cover story of Science Advances this week features a conceptual gastrointestinal (GI) microdevice, developed by a research team for extended drug release. Drug delivery platforms for extended drug release have proven to be challenging to develop in bioengineering due to gastrointestinal (GI) tract movements and their resulting elimination from the body. In a new report, Arijit Ghosh and a team of interdisciplinary researchers in chemical and biomolecular engineering, gastroenterology and hepatology, materials science, drug discovery, and neurology at the Johns Hopkins University in the U.S. reported new drug-loaded devices bioinspired by the grip mechanisms of parasitic roundworms known as hookworms. The parasites can linger in the small intestine for prolonged timeframes feeding on the blood of their host.
When an open theragripper, left, is exposed to internal body temperatures, it closes on the intestinal wall. In the gripper’s center is a space for a small dose of a drug. Credit: Johns Hopkins University
Ghosh et al. designed and developed a gripping construct they called theragrippers to dig their claws into the mucosal tissue of the intestinal tract. The devices performed gripping in response to body heat or other biological cues and released drugs into the GI lumen.