Diabetics patients tired of daily injections may have new hope in a less invasive alternative: Scientists at the University of British Columbia (UBC) have developed a new way to deliver insulin, which involves just a few drops under the tongue.
Diabetes is characterized by the inability to produce enough insulin to regulate blood sugar levels. People with type 1 diabetes, and many with type 2 diabetes, need to take insulin several times a day, usually via subcutaneous injection. This is not only uncomfortable, but also difficult for patients to follow and can generate biohazardous waste.
Less invasive methods are under development, with varying degrees of success. Experimental technologies include controllable implants and ultrasound patches that deliver drugs directly through the skin, but the main avenue of research is oral insulin administration — after all, popping a pill is easy and painless, and something many people already do every day.
But there are some problems with this: Insulin is a fragile molecule that can be absorbed into the bloodstream once it makes it from the stomach to the intestines. Encapsulating insulin in various materials, or creating a capsule and physically injecting it into the inner wall, might work, but this would mean that the insulin would first be metabolized in the liver, potentially changing its structure.
For this new study, the UBC team developed a new system, also known as oral insulin, but rather than being swallowed, it takes the form of drops placed under the tongue. This method, known as sublingual administration, works for drugs that don’t pass through the stomach. It’s effective because the tissue under the tongue has many capillaries that allow drugs to diffuse quickly into the bloodstream.
Normally, this method doesn’t work well with insulin, which is a large molecule that doesn’t easily pass through cells, so the team combined it with a cell-penetrating peptide (CPP), made from fish by-products that make cells more porous.
“Think of it as a guide that helps insulin get through the maze and get to the bloodstream quickly,” said Dr. Jiamin Wu, who worked on the study. “This guide finds the optimal pathway, making it easier for insulin to get to where it needs to be.”
The team tested the technology in mice. When combined with a CPP, the insulin successfully reached the bloodstream and controlled blood sugar levels almost as well as insulin given by injection. Without the guide peptide, the insulin tended to get stuck on the mucous membranes of the mouth.
The researchers are currently working to license the technology to commercial partners.
The system is described in two recently published papers. Controlled Release Journal.
Source: UBC
