Bioinspired, ingestible electroceutical capsules for hunger-regulating hormone modulation

Abstract

The gut-brain axis, which is mediated via enteric and central neurohormonal signaling, is known to regulate a broad set of physiological functions from feeding to emotional behavior. Various pharmaceuticals and surgical interventions, such as motility agents and bariatric surgery, are used to modulate this axis. Such approaches, however, are associated with off-target effects or post-procedure recovery time and expose patients to substantial risks. Electrical stimulation has also been used to attempt to modulate the gut-brain axis with greater spatial and temporal resolution. Electrical stimulation of the gastrointestinal (GI) tract, however, has generally required invasive intervention for electrode placement on serosal tissue. Stimulating mucosal tissue remains challenging because of the presence of gastric and intestinal fluid, which can influence the effectiveness of local luminal stimulation. Here, we report the development of a bioinspired ingestible fluid-wicking capsule for active stimulation and hormone modulation (FLASH) capable of rapidly wicking fluid and locally stimulating mucosal tissue, resulting in systemic modulation of an orexigenic GI hormone. Drawing inspiration from Moloch horridus, the “thorny devil” lizard with water-wicking skin, we developed a capsule surface capable of displacing fluid. We characterized the stimulation parameters for modulation of various GI hormones in a porcine model and applied these parameters to an ingestible capsule system. FLASH can be orally administered to modulate GI hormones and is safely excreted with no adverse effects in porcine models. We anticipate that this device could be used to treat metabolic, GI, and neuropsychiatric disorders noninvasively with minimal off-target effects.

Battery-free, wireless, and electricity-driven soft swimmer for water quality and virus monitoring

“…In addition, RF power would also be an important active source for in vivo applications in a wireless form. For example, using a magnetic soft robot ( 31 , 48 ) or an ingestible capsule device ( 49 , 50 ) as a carrier, the system can freely enter the body and perform the in vivo medical tasks, such as active electrical stimulation therapy.…”

Review article: Current status and future directions of ingestible electronic devices in gastroenterology

“…The myriad of therapeutic interventional techniques capable of being performed by electronic devices seems only restricted by one's imagination. For example, robotic electroceutical capsules that, by delivering controlled electrical stimulation to the enteric nervous system, might influence local motility, such as gastric emptying, 147 or the gut‐brain axis, such as by modulating hunger‐related hormones 148 and intra‐gastric balloon capsules for obesity management 149 are under development or have been proposed. Robotic control of gastrointestinal haemorrhage has been proposed based on the detection of bleeding detected by blood‐coloured pixels with subsequent inflation of a balloon from an endothermic reaction to apply pressure to the site of haemorrhage, 150 or by magnetically steering a device with a surgical clip in situ, which is able to be deployed at the site of bleeding 151 .…”

Luminescent ingestible electronic capsules for in vivo regulation of optogenetic engineered bacteria

“…The advancement in microelectronics has allowed for the creation of highly customizable electronic capsules. Ingestible electronic capsules can serve as alternatives to traditional endoscopies 20,21 and treat diseases by stimulating the intestines or delivering medication, including for constipation 22 or inappetency 23 .…”