2024-08-23 08:15:16
Heart failure is the leading cause of death worldwide and is especially fatal in people who do not have access to rapid medical facilities. With this in mind, researchers have set out to take heart failure screening from the lab to the home. Their prototype electrochemical biosensor, which resembles an outdoor urine test for COVID-19, can measure the concentrations of two heart failure markers in just 15 minutes with a single saliva.
The amendment is the work of Trey Pittman’s team, from Colorado State University in the United States.
“Our device will be designed for people who are at high risk for heart failure, but with limited access to a hospital or center,” explained Pittman. “Working on this project to address health disparities in rural or underprivileged areas is at home for me because I’m from Mississippi, where one of the highest death rates from heart failure is in the United States,” he confess.
Heart failure occurs because the weakened heart muscle cannot pump enough oxygenated blood through the body. The current gold standard for screening for heart failure is a blood test done twice a year by a healthcare professional, which measures levels of B-type natriuretic peptide (BNP), a protein that indicates the heart is working too hard.
However, new advances in field treatment devices may equal healthcare access with simple home saliva tests. This heart failure diagnostic test could be done by people to monitor health status every few weeks instead of every six months, as Pittman suggested. Until now, the widespread use of portable saliva tests for heart health has been limited by complicated manufacturing processes and a lack of useful data beyond the presence or absence of a single biomarker.
Pittman and his colleagues took on these challenges and obtained promising results with a low-cost, intuitive biosensor, which they call the electrochemical capillary immunoassay (eCaDI). Charles Henry’s group at the University of Colorado combined two of their previous innovations to create a portable testing platform: a saliva microfluidic device and a biosensor for the biomarker proteins galectin-3 and S100A7. Colleague Chamindie Punyadeera at Griffith University in Australia found that concentrations of galectin-3 and S100A7 in saliva correlated with heart failure outcomes.
The eCaDI heart failure consists of five layers: three layers of transparent, flexible plastic to other layers of double-sided adhesive.
The top plastic layer has small holes drilled into it for collecting the sample. The middle plastic layer has laser-cut channels with a square of absorbent paper on the end that draws saliva from the collection site through the channels. Between the outer plastic layers are fiberglass reagent pads that contain compounds that react with saliva and measure galectin-3 and S100A7 when an electrical current is applied to the device. The bottom plastic layer has a carbon ink electrode screen printed on the surface. Two electrodes, powered by small wire clamps from an external source called a potentiostat, drive the chemical reaction that takes place on the reagent pads.
A new saliva-based test for heart failure measures two biomarkers from a sample of saliva in about 15 minutes and can be done at home. (Photo: Trey Pittman)
“The devices are very easy to put together,” says Pittman. “In about 20 or 30 minutes, we can do five.” ECaDI is single-use and researchers estimate that each one costs about $3. Potentiostats, a small renewable energy source, sell for about $20.
In the demonstrations, researchers regularly spiked human urine samples with concentrations of two biomarkers that would indicate heart failure. The results show that eCaDI accurately detects the levels of galectin-3 and S100A7 in saliva. “These demonstrations are the first step toward a robust, non-invasive electrochemical sensor for heart failure monitors,” explained Pittman. In their next step, the team will examine the eCaDIs at Griffith University in research trials in healthy people and people with heart failure.
“This work could provide a starting point for new saliva analysis platforms aimed at detecting other diseases,” Pittman shared. “It’s a technology that I think could end up helping a lot of people, especially people who insecure, live long, healthy lives.”
This study, titled “Development of a microfluidic electrochemical biosensor for heart failure biomarkers in saliva”, was made public at a recent ACS (American Chemical Society) meeting. (Source: ACS)
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