Insulin Pills for Diabetes, Fact or Fiction?
Individuals who have type 1 diabetes must get their life-saving insulin via injection or insulin pump, while many people with type 2 diabetes also require insulin injections to manage their disease. What if scientists could create insulin pills and thus eliminate the need for painful needles?
Can insulin come in a pill?
Scientists at Brown University and Wayne State University have come one step closer to making insulin pills a reality. A major hurdle thus far has been the fact that insulin is a protein-based drug, and the molecules are relatively large, which can make them difficult to deliver efficiently.
Now, however, researchers, under the leadership of Edith Mathiowitz, professor of medical and engineering at Brown, have discovered that the small intestine is better equipped to absorb large molecules than originally believed. This information can now allow drug makers to get closer to developing a type of oral pill that might deliver insulin and other large particles to treat various conditions.
Mathiowitz and her team also recently reported another advance: that a special bioadhesive coating increased the absorption of nanoparticles in rats and could deliver substances to tissues throughout the body in a way that might be controlled. What could this mean to diabetes patients?
It could ultimately mean the development of biodegradable insulin-containing pills (as microspheres) coated with a special material that allows them to survive stomach acid and to then reach and be absorbed by desired cells in the intestinal tract—specifically, enterocytes and microfold or “M” cells. According to Mathiowitz, making such drug delivery possible “is basically what my future work probably will be.”
Other innovations in insulin delivery
In a study reported in May 2013, a team of researchers from various US institutions reported they had developed nanoscale particles that can be injected into the body and will release insulin when glucose levels rise. The study, which was conducted in animals, showed that just one injection of nanoparticles maintained normal blood sugar levels for more than seven days.
According to the study’s lead author, Dr. Zhen Gu, an assistant professor in biomedical engineering at North Carolina State and University of North Carolina at Chapel Hill, “We’ve created a ‘smart’ system that is injected into the body…and one injection was able to maintain blood sugar levels in the normal range for up to 10 days.”
While elimination of insulin injections would be highly desirable, significantly reducing the number of insulin injections, as this research has shown, would be welcomed by people with diabetes. Gu noted that the technology “mimics the activity of the pancreas in a healthy person, releasing insulin in response to glucose level changes.”
Rapid advances in nanotechnology are opening doors to new ways to treat diabetes and other common, serious medical conditions. For the foreseeable future, work on developing insulin pills and other oral drugs now unavailable in such forms is limited to the laboratory and lab rats, while Gu and his team are preparing for clinical trials in humans.
Gu Z et al. Injectable nano-network for glucose-mediated insulin delivery. ACS Nano 2013: DOI:10.1021/nn400630x
Reineke J et al. Can bioadhesive nanoparticles allow for more effective particle uptake from the small intestine? Journal of Controlled Release 2013 Sep; 170(3): 477-84