Author: Dhanavardhini Kalyanasundaram, Research scholar, Centre for Nanotechnology Research (CNR), Vellore Institute of Technology, Vellore.
To keep their blood glucose levels under control, people with diabetes frequently need to inject insulin several times a day. That's why I found it fascinating to read that bioengineers supported by the NIH have created a novel type of "pill" that could eventually eliminate the need for those uncomfortable shots. The source of inspiration behind their design? A Tortoise!
The new "pill," which is actually a swallow able device with a tiny injection system inside, has an African leopard tortoise shell-like shape. The design of the new device is meant to assist the animal in landing in the ideal posture to inject insulin or other medications into the stomach wall, much like the animal's highly curved shell allows it to quickly right itself when flipped on its back.
Fig 1. Tortoise’s shape inspired a new
insulin-injecting “pill”.
A THOUGHTFUL ARCHITECTURE:
“The more high-tech our lives become, The more nature we need" - Richard Louv.
A team led by Giovanni Traverso of Brigham and Women's Hospital, Harvard Medical School, Boston, and Robert Langer of Massachusetts Institute of Technology, Cambridge, took a novel approach to the issue by creating a tiny, ingestible injection system, which was published in the journal Science. Their pea-sized gadget is known as a "Self-Orienting Millimetre-scale Applicator," or SOMA for short.
The researchers knew they needed to create a design for SOMA that would properly orient the injection apparatus. Thus, they turned to the leopard tortoise found in Africa. They were aware that the tortoise's low centre of gravity and highly curved shell allow it to easily right itself if it tips over, much like a kid's "weeble-wobble" toy. The researchers used computer modelling to refine their design, starting with the shape of the tortoise shell. The end product is a polymer and steel capsule that has been partially hollowed out to contain a tiny spring-loaded needle that is tipped with compressed, freeze-dried insulin. Additionally, a dissolve able sugar disk is included to hold the needle in place until the appropriate moment.
Fig 2. Tortoise inspired technology
GEARS OF THE ARCHITECHTURE:
This is how it functions: as soon as a swallowed SOMA enters the stomach, it quickly positions itself so that the needle side of the device rests against the wall of the stomach. The insulin-tipped spring-loaded needle is released and injects its load of insulin into the stomach wall, where it enters the bloodstream, once the protective sugar disk dissolves in the stomach acid. The used SOMA device continues to move through the digestive system in the meantime.
A single SOMA can effectively administer insulin doses of up to 3 milligrams, which is equivalent to the amount a person with diabetes might need to inject, according to the researchers' pig experiments. Additionally, the tests demonstrated that neither the stomach tissue nor the surrounding muscles of the animals were harmed by the device's microinjection. Researchers anticipate that patients receiving insulin via SOMA won't experience any pain because the stomach is known to be painless. However, much more research is required to confirm the new device safety and its effective usage to the human community.
Fig 3. The Working Mechanism.
Once ingested, the device orients itself with the insulin spike toward the stomach lining. The sugar-based trigger then dissolves, releasing a compressed spring to inject insulin into the tissue.
Fig 4. Sugar-based trigger to inject insulin
“Look deep into nature, and then you will understand everything better.” — Albert Einstein
Einstein reminds us of the immense knowledge and insight that nature holds. By observing the intricate workings of the natural world, we can gain a clearer understanding of mysteries and find answers to questions that elude us.
REFERENCES:
Ø Abramson, Alex, et al. "An ingestible self-orienting system for oral delivery of macromolecules." Science 363.6427 (2019): 611-615.
Ø Abramson, Alex, et al. "A luminal unfolding micro needle injector for oral delivery of macromolecules." Nature medicine 25.10 (2019): 1512-1518.
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