US researchers have created a reusable hydrogel that releases artificial saliva over time, which could help provide sustained relief from dry mouth.
Their research is published in ACS Applied Polymer Materials.
Dry mouth is a condition whereby the salivary glands do not produce enough saliva. Many medications to treat dry mouth boost natural saliva production, but they either provide temporary relief or have unwanted side effects, including mouth irritation and tooth erosion.
Previous research identified that artificial saliva, often used in laboratory studies, could be a promising alternative to current medications.
Like natural saliva, artificial saliva is mostly water and contains mucins—a class of compounds that lubricate the mouth and have antimicrobial properties.
So, a team from the University of Wisconsin and Purdue University wanted to develop an artificial saliva reservoir that could be placed in the mouth and regulate the release of saliva over time.
To create the reservoir, the researchers mixed artificial saliva with a biocompatible polymer poly(hydroxyethyl methacrylate). The resulting hydrogel is a clear blob small enough to fit in the inner cheek or below the tongue.
To determine how much artificial saliva a single reservoir could absorb, the researchers submerged it in artificial saliva for six hours. The saliva gel expanded up to 400 per cent of its original volume, indicating that the gel has a high saliva storage capacity.
Next, the researchers tested the reservoir’s ability to release stored saliva. The gel released all stored saliva over a four-hour time span at 37 degrees Celsius, starting off a little faster and then slowing over time. This demonstrates that human body temperature helps initiate saliva release from the hydrogel.
The researchers also report consistent saliva release rates across five consecutive tests with a single reservoir, demonstrating its potential as a reusable treatment option. Lastly, cultured cells in contact with the gel had no change to their survival or growth rates, indicating the reservoir’s biocompatibility.
