Researchers have developed a new way to replace the loss of saliva or mucus on or in the body’s mucosa.
Many people have conditions in which their body does not produce mucus or saliva, protective fluids to keep various parts of the body well lubricated and functioning properly. These fluids can be lacking in the mouth, eyes or vagina.
Lack of saliva or inappropriate biochemical composition may prevent the tongue from sliding easily over the other surfaces in the oral cavity or the mouth may constantly feel dry.
This can harm people’s ability to speak or even to be able to eat food properly.
Disease, old age and medication can reduce people’s ability to form these fluids, but a solution to this problem may be on the horizon.
Researchers from the KTH Royal Institute of Technology in Sweden have developed a method to bind a hydrated polymer that mimics mucus in the mouth to the oral cavity, thereby preventing mucosal dryness and enabling the tongue to slide around the mouth as it should.
The research has been published in Advanced Healthcare Materials.
“People feel dryness in the mouth or eyes when the saliva or mucus lacks quality or quantity. This is a huge problem for hundreds of millions of people, and treatments are clearly lacking. We have therefore addressed this major and unresolved problem,” explains an author behind the study, Thomas Crouzier, Researcher at the KTH Royal Institute of Technology in Stockholm, Sweden.
Thomas Crouzier carried out the research in collaboration with Postdoctoral Fellow Matthew Blakeley.
Improving an existing lubricant
Thomas Crouzier and his colleagues started with an existing lubricant called polyethylene glycol. It comprises synthetic polymers and is widely used – also biomedically in connection with inserting implants, which must enter the body smoothly.
“We wanted to modify polyethylene glycol at the molecular level so that it could bind to the remaining saliva and mucus in the oral cavity and thus restore both hydration and lubrication,” says Thomas Crouzier.
Tested a lubricant on a pig’s tongue
To do this, the researchers functionalised polyethylene glycol with a sugar-binding lectin, a protein with a high affinity for sugar.
The body’s mucus has a high content of sugar molecules, which means that polyethylene glycol lectin binds strongly to the remnants of the mucus in the oral cavity, and the fusion molecule provides hydration and lubrication.
The researchers validated that the treatment works in cell cultures, and they have also tested it in a model in which a tongue from a pig sweeps back and forth in an artificial mouth and creates friction. The researchers tested the new fusion molecule and found that better lubrication reduces friction.
“We achieved stable binding that does not disappear when people rinse their mouth with water, and it lubricates well. In addition, lectin is extracted from wheat, which is already part of our diet. Based on the safety data we already have, we do not see any side-effects to worry about,” explains Thomas Crouzier.
Thomas Crouzier’s research group is applying for grants for the next steps in the research: testing the treatment on an experimental model that is closer to humans. They will also strive to increase the amount of artificial mucus that adheres to the inside of the oral cavity.
Then the next step will be experiments involving people, which can indicate how the treatment feels in the mouth and whether there are any side-effects.
Thomas Crouzier envisions that the lubricant can be applied as a mouthwash, a spray or perhaps as a special toothpaste.
In addition, he is exploring other functions of the lubricant, such as birth control or treatment in pregnancy by changing the mucus in the woman’s vagina. For example, the researchers are trying to strengthen the mucus layer between the vagina and the uterus so that it becomes impermeable to sperm, preventing unwanted pregnancy without hormonal contraceptives.
Another option is to alter the layer of mucus to which bacteria attach in the intestines. This may be used to treat various disorders involving the composition of gut bacteria.
“Changing the body’s mucus layer has great potential, and we are investigating various aspects of this,” concludes Thomas Crouzier.