Synthetic Coating Could Aid Digestion, Drug Delivery, and Disease Management: Study
Sat, April 10, 2021

Synthetic Coating Could Aid Digestion, Drug Delivery, and Disease Management: Study


A team of engineers developed a synthetic coating for the gastrointestinal tract. It could assist in digestion and drug delivery.

The synthetic coating for the GI tract was developed by engineers at the Massachusetts Institute of Technology (MIT), a US private research university. Although temporary, it could help medications for diabetes, infections, and other conditions. The film could also be used to aid the digestion of foods and drinks with lactose. Because it could interact with glucose, the film might improve obesity treatment. They published their findings in the journal Science Translational Medicine.

What is Lactose Intolerance?

Many tweens and teens do not get the recommended dietary allowance of 1,300 milligrams of calcium per day. Their body still requires that much calcium to fully develop their bones. An estimated less than one in ten girls and more than one in four boys, aged nine to 13, only get the minimum intake of calcium. If they have lactose intolerance, they are absorbing even less calcium than most people. It means they may be prone to osteoporosis later in life.

According to the National Institutes of Health, a US agency, teenagers have to maintain adequate calcium intake before the age of 17, when the growth spurts end. That is the time when 90% of their bones have been fully established. There will be little room for improvement as they get older. Sadly, getting older increases the chance of developing lactose intolerance, a condition wherein the body lacks the enzyme to digest lactose. Lactose is a type of sugar often found in dairy products, such as cheese and milk.

In the US, about 30 to 50 million American adults are lactose intolerant. The trend of this condition among races differs based on genetics and other factors. About 95% of Asians, 60% to 80% of African Americans and Ashkenazi Jews, 80% to 100% of American Indians, and 50% to 80% of Hispanics have high lactose intolerance. But in Europe, only 2% of Northern Europeans have the condition.



In a June 2019 study published on ACTA Scientific Nutritional Health, a peer-reviewed journal, a significant portion of the population of Syria could have lactose intolerance. A total of 354 participants aged two years and older were tested for absorption and tolerance of lactose. They were given milk and monitored for malabsorption and intolerance. After two hours of ingesting milk, 73.2% of participants were confirmed as lactose malabsorbers.

Out of 354 participants, 86.7% of aged three to ten years, 88.6% of aged 11 to 18 years, 95.4% of aged 19 to 40 years, and 95.3% of aged 41 years and older were lactose intolerant. But none of the participants aged two to three years were intolerant. The prevalence rates of lactose intolerance symptoms were bloating at 28%, stomach cramps at 48.8%, diarrhea at 54.1%, dermatitis herpetiformis at 12%, mouth ulcers at 8%, and vomiting at 3%. About 75% of male participants were intolerant compared to 71.3% of female participants.

Meanwhile, the European Dairy Association, an association of the milk processing industry in the European Union, estimated the frequency of lactase deficiency in several European countries. The frequency rates were 56% in Italy, 46% in Greece, 43% in Estonia, 40% in Hungary, 38% in France, 37% in Poland, 34% in Spain, 23% in Great Britain, 20% in Austria, 17% in Finland, 14% in Germany, 4% in Ireland, and 4% in Denmark. Lactase deficiency refers to the lack of the enzyme to break down lactose.



Synthetic Coating for Lactose Intolerance, Diabetes, and Obesity

At MIT, engineers worked on a project that yielded a thin, synthetic coating for the GI tract. It was initially inspired to help patients, particularly children, to swallow other drug formulations, alternatives to capsules. The polymer coating could ease the GI tract of patients and allow them to receive medications, without the discomfort. But the coating could do more than help drug administration.

"Children often aren't able to take solid dosage forms like capsules and tablets. We started to think about whether we could develop liquid formulations that could form a synthetic epithelial lining that could then be used for drug delivery, making it easier for the patient to receive the medication," said Giovanni Traverso, the senior author of the study and assistant professor of mechanical engineering at MIT.

The team experimented with polydopamine (PDA), a polymer naturally found in the sticky substance secreted by mussels. PDA is composed of monomers of dopamine, the same neurotransmitter in the brain. They found that an enzyme called catalase can assemble the molecules of dopamine within PDA. That enzyme is found in the digestive tract and expressed in high levels in the upper small intestine.



Using pig models, engineers found that if dopamine solution with tiny amounts of hydrogen peroxide, within safe levels, was delivered into the small intestine, catalase broke down hydrogen peroxide into water and oxygen. The oxygen helped dopamine to join the PDA polymer. In just a few minutes, a thin film of the polymer formed and coated the lining of the small intestine.

Because it can form in the digestive tract, the coating can be modified to serve additional purposes, aside from drug delivery. One of their modifications added an enzyme called beta-galactosidase to the film. The coating helped lactose intolerance. Experiments in pigs showed an increase in lactose digestion by 20 times.

Another experiment included praziquantel, a drug used to treat a parasitic disease called schistosomiasis. With the synthetic film, the drug can be given once a day – more efficient than the standard three times per day. The antiparasitic gradually released its active ingredients throughout the day. This approach is possibly useful in antibiotics that must be taken more than once a day.

And finally, an experiment showed the coating's potential in the management of metabolic disorders, such as diabetes and obesity. They successfully embedded the polymer with tiny crosslinkers. The modification made the coating impenetrable to glucose. This could decrease the absorption of glucose from food.

The synthetic coating can last for 24 hours and is shed along with cells of the intestinal lining. These cells are replaced constantly. Engineers are now developing a drinkable formula for human use and considering alternative formulations, including capsules and pills.