Ingestible battery offers potential relief for stomach conditions
Paper-based power source worked for three days in pigs and could help improve drug treatments for humans
Scientists have developed an ingestible battery that can power medical devices inside pigs for up to three days, in a milestone towards potential human use for health monitoring and treatments.
The paper-based battery, which was safely broken down in the animals’ bodies, could help with important tasks in the digestive system including drug release and the regulation of appetite-related signals, researchers said.
The development is part of a wider effort to deploy innovations such as tiny robots in the human body to improve the effectiveness of therapies and avoid the need for surgery.
“This moves the technology beyond a materials demonstration toward an integrated biomedical system,” said Giovanni Traverso, research leader and an engineering professor at the Massachusetts Institute of Technology.
The researchers behind the device are working with a partner to make prototypes for human use for a clinical trial due to start in about two years. If successful, potential applications include its use in therapies for conditions involving impaired gastric function, nausea or appetite loss, Traverso said.
The battery was made using magnesium–molybdenum trioxide, a favoured material for environmentally friendly electronics because it is well tolerated by the body in small quantities. This and the other battery components were encapsulated in melted beeswax and inserted by oral endoscopy into the stomachs of the live swine. The researchers chose the pigs because their gastrointestinal tracts anatomically resemble those of humans.
The swallowed battery powered a wireless tag in the pigs’ oesophagi that communicated with a receiver 1.5 metres away, according to a paper published in Nature Chemical Engineering on Monday. The battery was also able to provide the energy for a capsule that electrically stimulated the stomach for 20 minutes — an approach useful for human patients whose stomachs are slow to empty.
While the battery itself was bioresorbable, meaning it could be broken down safely in the body, the circuit board used for the stomach stimulation was not and was excreted naturally by the swine. Materials exist that could in principle be used to make more of the circuitry bioresorbable, Traverso said. Other next steps for advancing the battery system included launching larger safety studies, developing consistent manufacturing and testing it in a broader range of gastric environments, he added.
Stomach disorders such as gastritis are common worldwide. Gastric conditions can be hard to treat precisely with therapies such as drugs because of obstacles such as variations in the stomach’s acidity and the speed with which matter moves through the organ.
Researchers not involved in the ingestible battery work said the system seemed a feasible way of controlling and monitoring drug delivery. The combination with the wireless tag would be particularly useful for confirming that medicine had reached the stomach as needed, they said.
“The study offers a promising avenue towards improved transient electronic devices,” said Micaela Matta, senior lecturer in computational materials chemistry at King’s College London. “Swallowable alternatives such as this represent a key improvement with respect to devices requiring invasive surgery for implantation and removal.”